56 Top laners 51 Junglers 49 Mid laners 30 Supports 18 Adcs
I don't believe we should have 30+ Adcs by now since the fact that they AA a lot makes them similar, but maybe a few more adcs wouldn't harm, just to make botlane a little more diverse.
the issue is not the number of marksmen, but that ONLY marksmen are viable as duolane-carry. What you listed are not roles, it's positions, and any position can host multiple roles. Mid for example can have siegemages, contrroll mages, assains, marksmen etc, top can host anything from fighters to tanks to skirmishers to marksmen.
In terms of roles, marksmen actually have a quite big rooster, there are less than 18assasins in the game, and also less than 18 juggernauts, or enchanters and so on.
there are 133 champions......
I dont think we should get more adcs for now because adc as a role can only be played by marksman class of champion while other roles can be played by many different classes.
Actually Marksman subclass is the largest subclass of all (check here)).
Imo few new supports would add much more diversity not only to botlane but also to whole game as supports are allowed to have some crazy utility that whole team can use (Thresh's lanter, Bard's portals or Tahm's devour, to name few).
The problem isn't that there aren't enough ADCs, but rather that only ADCs can go bot lane (viably).
the problem with ADC's is that it is very hard to make them diverse. Unless you give them a new kind of auto attack or a reload, they all just do the same thing and they all build almost the same way. There just are not enough ways to make Auto Attacks unique and interesting, and when Riot does something like the shotgun attacks on Graves, its extremely hard to balance (although with Graves there were other problems besides just that). I really want to see some other role being able to be the bot lane carry besides marksman but it wont happen soon
There are some champions that could theoretically be used as botlaners that are not ADC though.
We need more aatroxes
And with more diverse Carries you open up the door for more diverse support styles and champions
