Most common method in blobbing is that you can't have hundreds of units normally able to fire in range, but rather a dozen or so in most RTS.
Most RTS encourage micro managing.
This.
AI War encourages micro managing to an extent as well, let's not pretend like it doesn't. If micro managing wasn't a part of AI War, it would be a TBS. At any given time you're moving your forces on the galaxy map, creating new buildings, creating new defenses, scouting (blatant form of added micromanagement), moving your blob around on an allied or enemy planet, moving your engineers around, creating priorities, or any of other dozens of things.
If Arcen really wanted, they could take away a LOT more micromanagement than they already have. Of course in the process they would be dumbing down the game wouldn't they?
What is the big difference between difficulty 8 and difficulty 10? Not how efficiently you use your forces on a tactical level, but how patient you are. Diazo spends 7 hours on 10/10 doing what a player could do in less than one hour on 8/8. Does it require extra micromanagement? Not really, it just requires being a lot more patient, and not minding the wait of the long build and travel times between every engagement.
I'll come right out and say I think this is flawed design. The skill level of the game shouldn't hinge on the patience of the player. The skill level of the game should hinge on the strategic and tactical ability of the player. Right now, there IS no tactical ability, you move your fleet around in a blob. Does moving your fleet around in 3 or 4 four blobs require more micromanagement? Yes, but not an unreasonable amount by any means.
And if you don't like micromanagement, you can play on the lower difficulties and still never have to do it. I would rather the higher difficulties be an exercise in micromanagement than an exercise in waiting around.
Micromanagement is part of an RTS. If you think it's not, you're fooling yourself. If the skill of the player has to come down to how patient they can be vs. how well they can micromanage their fleet, I'm going to choose micromanagement every time.