The recharge timers for calling the NPC is fine. All I would like to see is for the level cap of them to be raised in accordance with the level cap raises of player characters. Making theNPC cap 5-10 levels below what a PC can be sounds all right.

I also wouldn't mind a few more AI patterns either. Like one that doesn't debuff enemies and focuses on buffing/healing me :>. Especially with haste.