His puppet uses 80% of his Life/Def/Res, so improve those and you get better puppet. Also Nin is his worst growth by far, so improving it is not worth, it's probably the best one to take away from, my Kank is + Hp - Nin and he survives dragons from Fire Mains same power in ranked.

Shouldn't your Tobi have less hp then both of them unless he is hp mood as well, in that case it's even better cause AI is to dumb to ignore his dodge, it will just waste skills.