every ship shouldn't be able to solo another ship. A fighter plane in world war 2 could not SOLO a destroyer. But anyway... if I have a corvette type craft, which has more armor, shields, weapons, and power...it should be able to (once piloted half away decent) beat anything else solo or DRIVE off its attacker. Not because you want to imbalance things but by its very nature a corvette is more powerful than a fighter in any lore.
So if you are going to stick with conventional navy classifications, the least you could do is stick to why vessels are classfied higher, which is because they have bigger displacement and are more powerful.
A corvette, or anaconda or python being able to beat a fighter one on one isn't over powered...its normal. The resources it takes to construct a larger ship, you could construct several fighters for, and there is your balance. So if Navy 1 constructs a python, and for the same price and resources Navy 2 constructs 3 fighters, then yes I expect the three fighters to beat the python.
But the python or other bigger ship, punch for punch blow for blow is individually more superior than any fighter. I can understand nerfing the pythons maneuverability if it is bigger, but nerfing its shields etc...went too far.
So all multipurpose ships or corvettes are for, is cool to look at but functionally inept.