PBE Team Builder

Okay, I have been watching quite a few Team Builder matches/how it works on youtube. I myself am not in PBE, But one thing I see a lot is that when adc and support goes bot and support already chose their champion that might not fit the ADC they are playing with and this may bother some people. Now I think it might make the waiting time shorter because you are only choosing a role and lane and not champion, but before you start searching for a group instead of choosing your champion before, you only choose the role and lane you want THEN choose the champion you want for your role/lane IN the lobby so then the ADC and support both have Champs that could fairly work out. Example People in Lobby and its an ADC Ashe support Joins lobby and this person wants to support as Volibear ((yes I have seen Volibear support quite often)) now since Volibear is in the lobby he cant change his Champion in lobby because he has already chose BEFORE he started searching. Now if He could Change Champions in lobby she could verbally ask the Volibear to go another Support that would help Ashe a little better((of course this team comp could work)). Now being that I'm NOT in PBE I probably don't know everything and if i don't please correct me and comment what you think about this.

This is what an In game lobby may be like

Ashe Joined the Lobby as ADC

Wukong Joined Lobby as Solo TOP

Elise Joined Lobby as Jungler

Zyra Joined Lobby as Mid

Volibear Joined Lobby as Support

Ashe: I would like to have someone else then a Volibear as support.

The Volibear would then have to leave or be kicked If they all did agree, then the lobby would have to wait for a New Supporter. Now were if you COULD change champions IN lobby the Volibear could potentially of gone someone else as support instead of leaving.