Game doesn't really need any balancing maybe some very slight things but not much at all. Ivy is good at range and annoying like a zoner should be, she's weak up close but not helpless.
Nightmare and seig hit like trucks but have a ton of holes and unsafe moves.
At about F1 you really have to start knowing punishes and string or have great netural to win more than lose. Granted the way ranking is if you just keep playing you'll advance up, but eventually you'll get to people who are going to dominate random unsafe and button swinging.