Add Marketcenter and Cluster at map pool and if any of the teams wants to play those maps they have to play more serious at knives. So the knives will be more serious case between the teams and also it's the same if any of the teams doesnt want to play those 2 maps. So they will play serious at knives to eliminate those maps.
But in any case both teams will face the fact that they have to learn the maps. The first category to be good enough so the opposite team wont be able to beat them and the other category they will learn the map (at least the basics) to not lose with difference against the opposite teams.
And if any team doesnt want to play the map and they left or cancel the game they should lose the game by forfeit.