Combo's into level 1's are cheap simply because not every character can do it, OR has a reasonable alternative (i.e. Sly's can't be interupted, which is as good as comboing into a level 1).
Therefore, if every character could either combo into or had an uninteruptable super 1, then things would be fair.
E.g. Jak has neither. The mass inverter either needs to combo into level 1, or since its such a limited level 1 it should be like Sly's.