At all.
You can max a combat skill in a few levels and never worry about it every again.
If there are level requirements, that won't be possible in 4.
And you're using hyperbole when you say your damage fell behind heavily. That was not the case unless you had already maxed a combat skill, and were working on another. Or you were spreading yourself thin, in which case that makes sense; you're trying to master 5 different things at once and are going to have to take a hit in some department.
In fallout I can increase guns and energy weapons at the same pace, being a master of both with no requirement with perks. They only need cool and quirky things, they wouldn't make a weapon useless in my hands.