I actually think it's quite a good tier list. Or at least, I see a lot of higher-ranked players using Raiden and Kratos online. I myself am a Sly player and do quite well for myself, but struggle against those two. And conversely, I can dominate most Radec & Sackboy players.
It all comes down to timing and execution of supers though, which can be pretty unpredictable sometimes :P