You know how, in WoW, (or most of it's clones), you could queue for a dungeon, and just select what you wanted to be before you even entered the group?
After, all, if you just got random people, you would end up having 3 people wanting to tank, or 5/5 people wanting to dps. And then they'd fight, get frustrated, and give up, because the queue system is obviously flawed.
Well, why can you not implement a similar system into this game. You choose which positions you'd like to play, before you queue'd, thus, it matches you up only with a group that has a position open for you.
Sure, it would take longer if you wanted to be top or mid, but at least you would know that you aren't going to have to fight tooth and nail or say "mid or I feed" in order to get your position.
You may argue "But, there are no positions, you know how these pro players put the adc and support up top. Blah, blah, blah."
Well, first of all, you just stated 2 roles, ADC and support, but we'll ignore that.
Pro players also already play in their groups, who know where they are going. They aren't going to be affected by this. It should be for those who have to/want to queue with randoms.