Hit stun in mid air by SA1

Is there a science behind why sometimes your opponent will stay in the air for 10 or more hits of SA1 and sometimes only a few hits?

It seems to depend mostly on the size of the opponent’s hit-box, and would therefor be character-specific. I’ve noticed that Makoto, the shotos, Elena, Chun-Li and a few others tend to get hit more than the other characters. But even so, it does seem a bit random. Sometimes Chun and Elena only take a few hits, and sometimes you can hit them with all 20 knives. But generally speaking, I know it’s really hard to hit small characters like the twins and Oro. Sadly, I don’t think there’s any way to gaurentee 20 hits on anyone.

Yeah…it’s harder to juggle smaller characters with it in mid air. As a matter of fact…I was just playing some casuals with my friend’s Oro (MOD) and in one match I did SA1 from a good height in the air while he was in mid air and Oro was actually able to jump THROUGH the super and dash out of it. We have the replay saved and it gave us a good laugh. We had to watch the replay twice to figure out what the hell happened.