It was tested already, the chances are not exactly double, there's a topic somewhere in general discussion about it, @DeadGorilla dug it out.
She has counters, some very viable actually, mantine being a great example.
Sorry man I've been playing around with only 1 wall on what I'd call a really offensive team, and had no problem vs wall teams so far. We got wall breakers, mixed attackers, plenty actually.
Only 2 people have access to draco meteor iirc, from tournament prizes, meaning for other players is unavailable, therefor the ban, to keep it fair for everyone.
Because we don't need more RNG into the game(my point of view), but I'd like to listen to yours.