StarCraft 2 adapts their own 'Shared Armies' mode

I don't see why you would waste a full players attention on economy all the time. I'd rather expect high level play in archon mode to be about more tactics that involved attacks in multiple places.

That's just it: SC2 maps, especially for 1v1, are quite small. Not enough places to do more than perhaps two attacks at once; the unit cap also means you don't want to throw away 50 units to a concentrated 100 just to have your other 50 killed a little later.

Edit: forgot to mention, SC2 has econ mechanics that demand micromanaging as well. Devoting a player to nothing but larva spam and creep spread as Zerg, for example, would be tremendously beneficial.

As ShareArmy is the most outstanding thing in PA (yes, in my eyes it´s a real game changer), as it really focusses on TeamPlay and gives you so much more control of the action I can just appreciate this!
Really: The intense athmo and tension you experience while Playing PA in ShareArmy-mode is THE reason why PA is a must-play!