When in promo matchmaking should match you with people that play their main role

This is something that should be done long ago (and is done in other moba games like hots, you only get matched with people in promo). Why something like this should be implemented? We already have enough bad games coming from people who get autofilled and have literally no idea what to do or "i have no champ for x lane" and goes with something useless. At least in promos there should be only people who are either in promos or got their main role. It's not fun losing a promo because "got autofilled dont have any champ for top lane" or "oh sorry got autofilled support. let me take dmg dealer, not build sightstone and die 10 times in a row cause i dont know sht about playing duo lane". At least for promos match us with people who play their main role. Its unfair to get 2 autofills while enemy team gets to play all their mains.