"Urmm actually this could work out easier than you think. just throwing the idea out but. What if before the match both sides choose their counterpick maps?"
I was meaning to write something like this, but I think I forgot to mention it. What I meant by this was that when you enter your team you also select what maps you would like to use for games 2 and 3 if you lost the first or second game, so you'll be using the same counter pick maps for the whole tournament. And we can keep it to the same format of having one medium, small, and large map per set. So you would have to pick your maps based on that.
Ex.
My team
Counter pick maps: END, Entrance of Death city. (I don't know if these are small and large maps but you get the point)
I was meaning to write something like this, but I think I forgot to mention it. What I meant by this was that when you enter your team you also select what maps you would like to use for games 2 and 3 if you lost the first or second game, so you'll be using the same counter pick maps for the whole tournament. And we can keep it to the same format of having one medium, small, and large map per set. So you would have to pick your maps based on that.
Ex.
My team
Counter pick maps: END, Entrance of Death city. (I don't know if these are small and large maps but you get the point)