Okay, did anyone ever figure out exactly how stat distribution changes with Stance Change?

Because unless I'm severely misunderstanding how the Super Training stat map works (and based on all my other pokes' EVs, I don't think I am), in Aegislash's neutral form, he should have equivalent ATK and DEF stats, or at least very close (obviously he has an ATK+ nature, which the map may very well not show)... so what the fuck is with the monster gap between his actually listed ATK and DEF?

Game-canon treats EVs as "boosting base stats" (it uses those words) so I could see where what the game shows is BST + EVs, without counting IVs and natures, but EVEN WITH THOSE that type of gap just shouldn't be possible. Even with 31IV Def and 0IV Atk, the gap could not mathematically be that large.

It seems to me this confirms that Aegislash's stats are calculated differently; some sort of math is used to combine his Atk + Def and his SpAtk + SpDef, then those are portioned out to "mostly defensive" in one form and "mostly offensive" in the other.

It's clearly not purely a BST switch, or even a final stat total switch, otherwise in his default form his attack and defense would be equivalent.

Right?