It sounds like a good idea, but the viability is really going to be dependent on how the metagame develops. I've been testing Hawlucha fairly extensively, and Aegislash is almost always the go-to move for the opponent. More than 50% of the teams I've faced have carried one, and they hard wall any set that doesn't BP. Baton Pass works great because there's nothing they can do about it, moreso because they tend to Swords Dance under the belief that you can't really hurt them. Even if Sky Attack criticals and you grabbed a SD on Aegislash's switch in, it's not putting Aegislash in KO range of Acrobatics on the next turn, whereas Aegislash's own +2 Shadow Sneak will OHKO. And if it uses King's Shield instead, you'll have just wasted your item, your unburden boost, and your +2 from Sword's Dance and will be forced to switch out on the next turn.
If Aegislash usage drops, I can see the SA variant being a good wallbreaker, but it isn't going to do much whilst Aegislash is on every team.