Variable stat dudes - specifically with variable toughness - are generally considered too complex / having too much bookkeeping for common, which red-flags them at common according to NWO afaik.

Team Spirit is a func reprint of Odric's Crusader which was a common in foundations.

Huh, seems it was originally printed at uncommon, came down to common in Double Masters, and then got reprinted as such in foundations.

I still think it's a red-flagged at common. Note that red-flag doesn't mean it's a must-address necessary - the generally recommended red-flag percentage is under 20% of your commons, which in the case of simpler sets, with less of that quote 'spent' on new mechanics, can allow some more additional complexity elsewhere at common.

... Though it's worth of note that not all red-flags are equal and some are much more severe than others. Bookkeeping is one the 'annoying' sort where time can end up being spent on each side calculating how defender might end up blocking this as an attacker in differing ways can result in it dying. I can see that getting almost progressively worse the more you have these. Then again, if you don't have much other additional board complexity going on a set then this ain't that bad.

alternate idea: an ability similar to that of "orphans of the wheat"