very hypothetical fight
1) The civilization of dinosaurs. At the time 100 million years ago. Time one of the largest dinosaurs. Many 7 tons acrocantosaurus and 10 tons Giganotosaurus. Also, many utahraptors. Relatively small, but ultra dangerous creature.
Human civilization in the time of ancient Greece. World population of about 5 million. First Army. Antic phalanx. Have stone buildings and cities. Advanced culture. Just the power of human civilization precisely at the level of ancient Greece.
2) 7t acrocantosaurus vs 6x 1t caffer baffalo (they have a good organization)
3) 10t giganotosaurus vs 8x 1t caffer baffalo (they have a good organization)
4) 3t indian elephaness vs 2x 350kg amur tiger
5) 350kg giant forest hog vs 280kg bengal tiger
6) 350kg giant forest hog vs 350kg brown bear
7) giant forest hog vs wild boar (pariti)
1) dinosaur groups vs ancient civilization: The weapons primarily used by the humans will be spears, and armor (helmet, breastplate, etc) & shields will be utilized as well (if I have this right!). Remaining within their stone fortresses will offer protection from marauding dinosaurs, and fire may be a valuable commodity as well. It's easy to assume that the dinosaurs here will act the same way they are depicted in movies (like the Tyrannosaurus & dromaeosaurids from "Jurassic Park"), but we can't be sure. It might not be a "Land of the Lost" reenactment where the huge dinosaur is always trying to break into the fortress, but who knows? I imagine the army will be vulnerable upon venturing out, as their armament won't be sufficient enough to repel every dinosaur (especially the swift Utahraptors) every time without significant casualties. The spears thrown may slow down a Giganotosaurus eventually, but not before it crushes several humans (armor & all) in its jaws. An encounter really depends on the numbers on each side, so there will be some victories and some losses. If the armies take on the role of hunters to ambush the threats (and reduce their numbers), they may have a better chance of survival each time they need to march to another area, but they will be safest staying at home. Hard to visualize with great accuracy how this will play out, but I'd imagine the same principles that apply with, let's say, the beaver (safe if it remains in its lodge, potentially vulnerable to predation when it ventures out) apply here. Without advanced long-range weaponry, the armies won't be guaranteed success away from the fortress. Another factor to consider is the availability of prey items (other than humans) for these dinosaurs. If there is an abundance of sauropods, hadrosaurs, ceratopsians, etc., the humans won't seem as appealing. A lion would rather capture a zebra than a springbok (more meat to eat), and the same principle might apply to Acrocanthosaurus, Giganotosaurus, and Utahraptor. The humans will be better at adapting, and their advantages will increase as time goes by. Interesting question!
2) Acrocanthosaurus (7t) vs 6 caffer (Cape) buffalo (1t each): Acrocanthosaurus was a huge theropod with fearsome jaws & teeth, and was practiced at the predation of animals much larger than a Cape buffalo (like Sauroposeidon at approximately 40 tons). Cape buffalo occasionally form a group in defense (strength in numbers) against attacking lions, but a group of herbivores working together is generally not as effective as a group of predators working together when the adversary is much larger. For example, a group of grey wolves weighing between 50-55kg can successfully tackle a large elk or moose (possibly weighing at least 10 times as much as a single wolf) on occasion because they've evolved to do just that. An Acrocanthosaurus will likely send a herd of Cape buffalo into a panic, and even if the bovids choose to stand their ground and actively resist, they won't have the same kind of success they sometimes enjoy against a pride of lions. The Acrocanthosaurus can kill a Cape buffalo with one bite, and the horns of the bovids won't have any significant impact against a creature of this size. Acrocanthosaurus wins.
3) Giganotosaurus (10t) vs 8 caffer (Cape) buffalo (1t each): Giganotosaurus was a huge theropod with triangle-shaped serrated teeth (20cm long) set in massive jaws. This dinosaur commonly fed on sauropods including Andesaurus, which weighed approximately 7 tons. As with the last matchup, the Cape buffalo won't do well against a creature of this size, and can be dispatched by a single bite. Even if the buffalo were infused with an unnatural level of aggression that caused them to recklessly attack all at once without regard to their own safety, they wouldn't make enough of a dent before being picked off one-by-one. Giganotosaurus wins.
4) Indian elephant (3t) vs 2 Amur tigers (350kg): The Indian elephant used here will measure about 2.7m at the shoulder. Bengal tigers will seldom hunt in pairs, and it's possible Amur tigers would if the situation arose, but this elephant weighs almost 8 times as much as each of them. Groups of lions have tackled elephants in certain areas of Africa, but a large group is required. Tigers are amazing hunters, and the 2 Amur tigers aren't without hope, but the elephant (whether male or female) will be too powerful on most occasions if it's healthy. Big cats don't have the greatest endurance, and it's unlikely the Amur tigers will inflict enough damage or secure a killing bite in the window of time they'll be granted. You can imagine how difficult it will be for a pair of lionesses to tackle a single Cape buffalo weighing 4 times as much as they do, and the elephant in this scenario weighs almost 8 times as much as each member of the tiger tandem. Edge to Indian elephant.
5) giant forest hog (350kg) vs Bengal tiger (280kg): Giant forest hogs among the largest of all suids, and have stocky, durable bodies and sharp tusks that can be used to effectively defend themselves. The tiger's quickness, agility, and killing know-how will be great assets, but it will need to be careful in a face-to-face encounter. Large suids can present a unique challenge for any big cat due to their tough hides, formidable weaponry, and good lateral movement. The tiger will need to use its forelimbs (and claws) to control the movement of the giant forest hog's head, and apply a finishing throat/spine bite while the tusks of the suid are neutralized (and may use its body weight to knock the hog over before biting it). The tiger will be driven away on most occasions without the benefit of an ambush, but has the tools to succeed if it's careful. Bengal tigers are superb hunters that can ambush & tackle large buffalo/gaur solo, but ambushing is a bit different than squaring off with an opponent face-to-face. Realistically a hog this big will have the advantage, but a tiger determined to battle to the end (which isn't typical with a solitary hunter) will have a decent chance. Close to 50/50.
6) giant forest hog (350kg) vs brown bear (350kg): Brown bears have typical ursid attributes (strength, endurance, durability, jaws & claws), and are the most formidable (pound-for-pound) among bears. They typically have pronounced shoulder humps, which give them great power in their forelimbs, and can deliver a paw swipe with great force with a paw armed with claws 10cm in length. Giant forest hogs live in Africa and don't encounter bears, but have the means to deal with one in a battle (tough hides, sharp tusks, good lateral quickness). Brown bears can be aggressive & confrontational, and depending on which one is used, occasionally deal with adversaries close to their own size. Siberian brown bears battle Amur tigers on rare occasions, and grizzly bears predate on moose & bison from time-to-time. In many locations brown bears predate upon wild boars. The bear's forelimbs (and body weight) will need to be used to control the anterior portion of the giant forest hog's body to keep the tusks at bay. In a realistic encounter the giant forest hog will probably drive the bear away, but a battle between determined individuals will slightly favor the bear. It will have more strength, more diverse weaponry, and greater stamina. Edge to brown bear.
7) giant forest hog vs wild boar (at parity): Giant forest hogs are the largests of suids, and have a stocky, robust build. A wild boar of equal weight will be slightly more slender, quicker, and may have a higher level of aggression (all of these attributes may vary from region to region). Giant forest hogs occasionally deal with leopards & spotted hyenas. According to "The Illustrated Encyclopedia of Animals of Africa Britain and Europe" by Tom Jackson (in regards to the giant forest hog) "males are aggressive, will charge intruding males, and have also been known to charge humans". This book also states (regarding wild boars) "male wild boar can be very aggressive. In Doņana National Park in Spain, they have been known to chase adult lynxes away from carrion". The tusks of the giant forest hog are generally longer (usually by 1/3), but the slight quickness advantage of the wild boar probably neutralizes this advantage in regards to ease of weaponry use. Both can certainly win, and this may largely depend on the individuals involved, but I give the slight overall edge to the wild boar.