Shirley, this has been mentioned before

[Lusiphur Malache]

How about a support/pet AT? Could call it a Buffmeister. That might need work shopping 

[battlewraith]

How dare you.

[golstat2003]

Why you calling us Shirley man????

[MTeague]

Essentially a Mastermind, but with primary and secondaries flipped?

 

I'm not sure I see the point. From lvl 30 onward, you would have access to all of the same powers, AND, your summoned pets would be a fair bit weaker, since the pets would be your secondary tree. That would be a necessary trade-off in order to have Defender level buffs/debuffs from your primary. 

[biostem]

I'd rather some sort of frontline fighter MM...  something like removing the MM's own attacks from the pet sets, replace them with theme-appropriate general armor toggles, then give them a melee or assault secondary, (or maybe blaster manipulation sets for flavor)? 

[Lazarillo]

14 minutes ago, biostem said:

I'd rather some sort of frontline fighter MM...  something like removing the MM's own attacks from the pet sets, replace them with theme-appropriate general armor toggles, then give them a melee or assault secondary, (or maybe blaster manipulation sets for flavor)? 

An Assault/Henchmen AT done pretty much the way you're describing, is one I suggested wayyyyyyy back when.  IIRC, I called it the "Vanguard", though I realize in retrospect that's kind of a loaded term in the game.