Scott is hard to place. I don't think many can argue that he didn't bring bumpcav to NA (For better or for worse) and he was pretty unstoppable early on when many of the top UNAC 1 teams didn't even exist yet or their members were in other clans.
But yeah, by the time UNAC came around and other clans had cav capable of bump cav + just being solid cav (and more importantly, being able to do it on a hunter instead of a warhorse) he kinda faded into the background.
It really comes down to how highly you value his performance in the 2010-2011ish "era" of Warband and how highly you value him more or less starting that meta in NA. 7th best cav overall in NA? Probably not. Worthy of being somewhere on the list of top 25, probably.