If you think about it there are barelly any footage of rickson rolling besides his mma fights, where he showcased a very basic takedown/mount/gnp/armbar or rnc from the back finish against every single of his opponents. There are a few very short videos of him rolling with his students, this very low quality footage of him where he takedowns a guy in a sambo competition, and maybe a few gracie challenge performances. The only video of him rolling against a high level bjj competitor is that footage of him going against rolls gracie (and he looks very impressive in it). So unless you were a student of him, and had the chance to see him rolling in real life, it's like impossible to vizualize how his bjj style actually looks like...