What if we just altered the CDs for attacks and abilities on the pets? The biggest complaint I've seen for Mercs has been the fact that all of their major stuff (CC for Spec Ops and the rocket for Commando) are on awfully long CDs to the point where the pets are almost useless. Obviously not all sets would have the CDs heavily reduced, but what if they were closer together? I totally understand that there is going to be different things to consider with each pet's abilities, as giving CC the same CD as a massive damaging move could completely make one set scores beyond others.
Pet level syncing with Incarnate stuff would be nice but I can't imagine the difficulty in trying to achieve such a task with how messy the pet code must be.
I'd like to see higher scaling stats across all sets for pets the closer you get to 50 to help with both survival and viability, but I don't know if I'd want to see damage numbers any higher than base (sans tweaking one or two sets). I'll admit I've not compared numbers with Defenders so maybe the pets do need better damage scaling, but then it brings up the question of what role does the MM actually fit in? I know they were intended to be Tanks back when they were released and have fallen into more of a weird support role with six sentient weapons that does their bidding, but should it be more of a damage role? This would hover around the unfortunate homogenization of the power sets across the board by changing the level 18 to an actual pet attack/buff, flavored for the set, and usable as a mandatory ATO/Buff tax within it. The easiest way to do this would be summoning temporary pets flavored by set with a possible buff to a pet or an ST debuff from the temporary pets themselves.
Or we could embrace the original idea for Masterminds, give a taunt that buffs the pets with gauntlet for a very short period and crank up the stat scaling for pets. This would give lowbies the feeling that they're not better than a Tanker or Brute but can still feel like they're able to pick up mobs as needed. At higher levels there would be arguments for MMs replacing Tankers and Brutes for the purpose of tanking since the pets would have gauntlet, especially those Time MMs who would absolutely find a way to perma-buff the pets with gauntlet and just abuse the heck out of aggro caps.