I never meant it would be 10-0 or even 9-1/8-2 matchups, 6-4 and 4-6 matchups ar what i imagined in this situation. every character gets advantages and disadvantages, but not glaring ones like that. maybe each character gets a few 6-4 matchups in either direction and maybe even (very few) 7-3/3-7 matchups, but an equal amount in each direction as well. Of course these estimates aren't accurate to what a perfectly balanced game would be, but i think you get the gist of it, a player might have a disadvantage but if he or she is good enough then it won't matter much.
I can't imagine a 5-5 matchup for every chracter truly existing, so getting it close and with an equal amount of slightly good and bad matchups, i feel the same effect can be achieved.
tl;dr: no character should have a counter, but have slight advantages and disadvantages over others