Just a team diff,aim diff,strat diff
Not necessarily. I think FPX has a good map pool outside of their Breeze. PRX also bans Breeze and Split mostly. So if FPX reach the final it will be a map pool of Ascent, Bind, Haven, Fracture and Icebox. FPX have the best Ascent (on par with LEV) and a decent Fracture as well. Their Bind and Icebox are also decent. I can see a scenario where FPX lose 2-3 but it surely won't be a 3-0.
someone made this Optic vs FPX stats
https://mobile.twitter.com/willminder/status/1550732065800331264