Clash of the Classes

So, basically I came with an idea for a new game mode. It is called Clash of the Classes. Basically, you and your team would be locked into a certain class, and the other team would be locked into a different class. I don't know where it would be played. Either Summoner's, Twisted, or Crystal Scar.

Ex. Marksman vs. Mages

To help with people not having a certain class type, Riot could add them to a free to play rotation. :D

What do you guys think? I came up with this out of curiosity of what would happen and would this would be like.