I think Mago has been really clever with how he's approached this so far. I wouldn't be surprised to see him get quite far in Capcup.
I've heard it attributed to Mago that one of the reasons he took up Yang is that, while not a great character overall, he matches up well against the top tiers. I can't claim to know the matchups enough to confirm, but if that's true, and I've no reason to distrust Mago, then it's potentially a pretty brilliant move.
Interesting to note is that at Final Round, Mago took out some strong players and ultimately lost to two Bisons (Hiro in pools, Tampa Bison in top 16)
More than anything though, the dude was just playing tremendously at Hypespotting