Simple suggestion.
When you hand over a pet to a pet trainer, that pet gets unlocked for use by your heroes. You can select to use this pet, or well one with the same species, level and evolution, when you equip the charm animal skill rather than go out and charm individual pets for your heroes.
Or in other words, I can go out and charm a bear/rat/crocodile/flamingo, level it up, hand it over to the pet trainer to unlock bears for my heroes.
Then get a whole bear army by making them all rangers and giving them a bear pet.
I'd still have to charm another bear if I wanted one myself, but at least it'd just be two trips and two petleveling grinds. Not one for each hero.
g

