So in one combat I had three DPRK Corps intermingled, the front was just tight. Because of this I could get HQ support to one combat from 3 separate HQs (so a total of 6 column shifts). The penalty for this was a +1 Multi-corps DRM, which in this case was offset by the fact they were assaulting from 3 hexes. The defender had 1 HQ to support them (though others could of assisted if allowed).
It seems to me that the column shift benefit of HQ support trumps the +1 multi-corps DRM.
Am I missing anything here?
It's +1 per additional corps (so would have been +2). Other than that, no. I actually like the alternate play rules better, but it makes for a more difficult game (for both sides really).