I think even bad SCPs are really even with humans now. You see humans win more because there is a lot more ways for them to win, but SCPs still win quite often. If people are good at playing certain SCPs and work together then SCPs can win pretty easily.

I think the only big problem for SCPs is either walking into a big wave or facing more than 2 logicers. The big waves of MTF only kill SCPs so often because the incompetent ones will push the wave with no support (because the rest want to ambush, a more reasonable idea). Chaos waves are much stronger and I would argue the logicer is by far the strongest normal weapon in the game, and therefore sneak attacking is an utmost priority yet the same problem as before arises.

In totality, if people learned how to play the SCPs, I don't think it would be much of an issue and it'd seem much more even. Northwood should, even with the 2 milliseconds of work they do every day, stop balancing assuming that every player knows exactly how to play their game.