If you like team builder better than dynamic q, I have a suggestion.
How about you can choose two roles if you want, but you could also choose one role. For example, Lets say im a jungle main, but i suck at everything else. Why would I have to put a different role for secondary like top which im not even good at top and I have a good chance to do bad? In team builder you could select one role, and I think dynamic q should have that as well.