Yes, Elginb does make good points.
Mechanically, I think Mind Exchange was a way to cut down on the Marvel squad-killing threats. The first 10 heroes already include strong anti-swarm, and the designers seem to be going out of their way to make sure the best squads, both common and unique, can go up against the best heroes and have a chance to prevail. If Doom's supply of death lasers, double attack, and explosion is too good against squads, the pendulum might swing too far toward big heroes mowing down squad figures left and right.
Tossing in a few powers that can't hurt an enemy's squads is part of maintaining that balance. As things stand now, an opponent can avoid the effects of Mind Exchange and Cosmic Force Blast by sending squads into the fight, and the Marvel single-attackers remain somewhat vulnerable to low-cost hordes.
EDIT: Woah, you know what I just now realized? The Marro Hive's common-activating power is a reveal-order-marker-only, just like Red Skull. But the rest of the previewed command powers are "instead of taking a turn with" wording! That means that Dr. Doom can:
1. Mind Exchange his own or an enemy Ulginesh and instead take a turn with two other Elf Wizards he controls within range,
2. Mind Exchange his own or an enemy Kato Katsuro and take a turn with a samurai hero, samurai squad, or two Ashigaru squads he controls within range,
3. Mind Exchange his own or an enemy Hive and have a chance to raise a common Marro you control!
Add in the fact that Red Skull's manipulation can chain to the command powers of Kato or Ulginesh, and that he can also manipulate Shiori to do her best work. Plus, Tor-Kul-Na seems like he'd be a great partner for Doom, because Doom is anti-hero, and TKN is a big, durable anti-squad beater for when the enemy brings a swarm against him. Everybody's been nominating Captain America for the guy most likely to find a home in mixed games, but it seems to me that with the release of SotM and Wave 8, Red Skull and Doom are going to become equally or even more desirable in mixed games in the 700+ range.
And then on top of that, the Nagrubs will allow you to choose whether to activate TKN or Su-Bak-Na or the new Hivelord.... With Doom at 245, Red Skull at 190, Kato at 200, TKN at 220, and Ulginesh at 150, suddenly it starts looking pretty easy to build a 700-point army or beyond that has a manageable number of army cards and is going to give you a choice of who to activate on a big proportion of your order markers. Sorry, I'm rambling. Probably I'll find out tomorrow everyone else already thought of this weeks ago.