I'm kind of surprised Shuma is so high on support- I guess he thinks the assist is THAT good, because the squid doesn't offer much else in terms of support that I'm aware of. Then again, a lot of the support placement seems really random. Ryu is a better support character than Storm (neither has great assist options but hailstorm DHC and reliable omni-directional infinites make Storm much better, IMO)? Magneto is straight mid tier support despite having the best beam assist for teleport mix-ups and the easiest omni-direction TAC infinites in the game? Vergil around mid tier for support despite him being a walking DHC glitch, and letting you DHC into spiral swords giving you complete control of the match for its duration?
Really, the support stuff flat out goes against reality. There is not one human on the face of the earth who has actually picked Ryu as a support character, while Vergil is one of the most used support characters in the game, Yipes has won tournaments with Magneto in a support role, Justin Wong makes Storm work as a support (not as his primary assist character though), and hell- Spencer is mostly played as a support character these days, haha.
And how can Phoenix not be bottom of the barrel for support? Like, she's literally an anti-support. You cannot ever call her as an assist (outside of combos) and she makes it so your point character has FEWER options due to her inherent nature forcing you to restrict meter usage. Also, why isn't Dorm near the bottom? He has one barely usable assist, his DHCs in are just decent, TAC options are so-so, etc. etc.
edit: as always, individual character tier lists are dumb anyway, haha.