I think that one should be careful about the concept use of the word 'pack' as opposed to 'close proximity'. Very few (by comparisons to total count) medium to large carnivores alive today actually hunt collectively in very large family groups, outside of some of the apes and monkey families. Almost all the big cats, expecting lions of course, hunt solo, although their territories do cross from time to time and for mating. Small family groups are the exception, until the cubs are full grown and these usually exclude the male. The dog families, or 'dog-like' families tend to be an exception with wolves, dholes, hyenas etc. actively hunting in collaborative groups to bring down larger prey that they could not hope to tackle alone. However, where prey congregates, predators do too, and during certain seasons they are known to forego the usual solo attitudes and remain and hunt closer together. Yes sometimes squabbles ensue, but by and large the ygenerally 'co-hunt' in the same area and the same prey but not working 'together' as a pack.
In the bird realm, if we tie that thread to dinosaurs (or at least some of them), how many carnivorous birds hunt in packs? Birds of prey are solitary, scavengers are not, or rather scavengers tend to 'congregate' and 'tolerate' rather than hunt of course. Just how a carnivorous bird would hunt in the air in a 'pack' I am at a loss to visualise. Is this left over from dinosaurs heritage - unlikely, It is more so the product of practicality of in-flight or flight-to-ground hunting.
In the marine environment, discounting the whales which form large family groups and obviously actively work as predatory groups e.g. dolphins, sperm whales, orca etc., the other species can be very mixed and curious and some very different species (fish and octopus) have even been known to 'cooperate' which could be termed 'pack' hunting mentality but it is usually limited to one or two members rather than a large group. Sharks tend to congregate in areas of high prey and they hunt in close proximity to each other but not 'collaboratively' in the same way that Orca do for example. Smaller sharks such as reef sharks and white tips could be said to hunt in 'packs' in that they form large groups that hunt the same fish in an apparent collective, but they squabble over food - there is no apparent 'hierarchy' to the 'frenzy' so often seen - it is simply the practicality of hunting in an aquatic environment, perhaps.
Crocodiles also hunt in close proximity. Many individuals will laie in close proximity in the water near crossing points to grab the next prey to come by - again, they are not collaborating to achieve a goal but they do get close to each other and they do bicker over food. Size tends to dominate the victor in that fight. The same can probably be said to the relatively few and far between large ground lizards like the Komodo dragon. Smaller lizards tend to hunt smaller food and tend to eat it in one go, more or less.
I think what is fair to think about is not what we know about whether they had the mentality but what drives these actions: Smaller species tend to form family groups and collaborate - life is tough if your very small after all. We know that herbivores generally stick together - safety in numbers - but small predators can, and do, the same from time to time. Small predators when acting together can bring down larger prey - though this seems limited to the dog families and larger mammal family groups of mother and usually one or two offspring. Medium dinosaur carnivores (velociraptors) would probably be more capable and able acting alone - more like a tiger than a lion for example - but you couldn't rule out the lion theory for them either - a group of raptors could bring down a large herbivore BUT would they be able to protect it form a large carnivore that would inevetibly come by drawn by the smell? Probably not - but that may not be a nullifying factor all the same. Larger carnivores would almost certainly hunt alone - simply because they require so much more protein to survive that competing together would not yield the same value. However, they may end up in close hunting proximity if prey species were sufficiently abundant, but smapcially limited, to allow that to happen.
Ecology usually has more of the answers than our theories, but who knows for sure with dinosaurs? At the end of the day its a game and they are genetically modified, living in unusual environments, and can act in unusual ways so maybe we just think of what might be more fun than allegedly 'accurate' to real life.