I think there's a good mix of difficulties and it's nice to have a challenge sometimes. You do need to build a good number of explore wolves or use potions and this will be even more so now that there are so many explore moves so it will be interesting to see how this balances out in future.

I think they are all pretty good except for elephants and bears sometimes when they come in big groups.

its kind of a 50/50. some are killed with a one-shot and on some it seems like eternity before they either flee, are killed or have taken your team out. some also are just impossible to tackle. the easy ones also have a major drawback (mostly the rabbits and squirrels). while they are easy to kill, they more often than not also flee either instantly or just riiiiiiiiiiiiiiiiiiiiight before landing the killing blow on them wich is making hunting for food pretty difficult more often than not. a seperate hunting feature would be a great help here. also the bosses and most of the event encounters are too hard to beat for newer members with still "weak" wolves. they need a major tweak. they also just flee way too often, mostly already after you made your first attack wich lets you stand back like ordered but not picked up.

I think that the NPC's are balanced except for in jungle. I have all together skipped elephants, for I have 4 teams and barely have two survive after getting the 6 elephants, so I don't battle them anymore. Same with the Six sun bears, although you have to go through them, usually taking at least one explore team.