This is how I see it.
Alice is the top one because she kills 6 members of the cast almost automatically with her air-CD infinite and she can hold her own with keepaway and good air moves. Kang’s too quick for a grappler, has the best projectile in the game and he can combo into his throw super. Billy and Lynn are just that good all around, strong specials and good anti-air supers. Jimmy would be higher but if he gets wrapped into the Alice infinite it’s over, so he’s 5th.
Oni and Pepe have good, hard-hitting combos, Elias can do life-gain combos with walls and has an anti-air CD, Pupa has a great mix-up game, Cassandra can combo into her CD and can be annoying if played right, but she doesn’t have enough defense and you have to work for your win.
Sonia’s only good with Jimmy (duplex into Jimmy’s CD), Jones is too slow and too limited, Radel doesn’t have any good matchups or pairings and has laggy moves, and Annie’s just terrible.
edit Forgot Kang can get infinited too.