A tough mob (high hp) will loot a lot of something. As fine hide is a higher TT, the minimum TT drop needs to be above the TT value of fine hide. i.e. don't expect as much fine hide to drop from small bery as does from neconu in the same ped ammo hunt. Soemthing like thorio drops it regularly and a lot - however thorio are notoriously uneven loot mobs - you can get 5 or six non looters, then mini after mini or global after global on them. They are a very difficult mob to camp
but when they loot they loot high.
If you really want lots of fine hide - go on a team hunt for tough mobs, definitekly quickest and surefire way.