Not sure about this. How would you decide it? Would the player specify it (and risk people lying, or people not changing it when they change their class), or automatically based on builds or something else? (would have to account for all hybrids and might get people as cav when they rarely play it)
Also, I suppose you would take into account the main, but what if someone plays much more on alts than on their main?
If there is an easy way to solve these possible problems, and it would be relatively easy to implement, all for it, but otherwise I do not think it worth doing.