I just skimmed through the leaderboards, assassins are overrepresented in their usage to get very high
Marksman are too dominant in all mobas I played.
Did you divide the numbers by the numbers of average count in draft (I’d say 2.5 assassins/specialists, 1.5 tanks and 1 support should be close to accurate for current meta) or did you just count the number of players that have most games on assassins (because that’s what you will see for literally every flex player, because the draft needs most assassins)?
I haven’t looked lately, but I’ve did the math a few seasons ago and no class seemed overrepresented in the top200 (it had even more assassins overall then though, since most popular offlaners were assassins then).
Also, tank and support mains still get to top spots and don’t need to grind more or less than assassin mains (e.g. #2 Cronaz - an ex-Illidan-main, turned to support main by HGC).
So nope, your statement is most definitely not true.
Most people DO find playing assassins more fun (me included), but that has little correlation with chance to win ( for me, supports are easiest (but also most boring, so I’ve played supports the least) and tanks are hardest). If I wanted to just grind rank for whatever reason (I can’t figure out one, fun is still main factor for me), I would play supports only.
What others have said above = Assassins in general average about 2+ per game since it’s least 2 every game (up to 3 I suppose ?:P), whereas tanks are usually 1 main tank but often offlane role can be played by a melee assassin as opposed to offtank/2nd-warrior
That being said = even for those that don’t main assassins => the highest chance is they play a one if there’s no further need of 2nd supp or 3rd warr