Fighter/Rogue Substitution Abilities

[AtwasAwamps]

I recently came across the "Feat Rogue" and "Sneak Attack Fighter" ACFs and was wondering...

How overpowering would it be for me to provide my players with the option of taking "Substitution Levels" in those...IE:

A fighter is gains a level where she would gain a fighter feat. She has the option of instead taking a sneak attack die, losing her fighter feat.

A rogue is coming up on a level where he would gain an extra die of sneak attack. Instead, he can trade that damage die for a feat from the same list as a feat rogue.

Would this overpower these classes/roles? I thought it might be an interesting experiment at the very least.

I am considering doing the same for rangers/paladins with the non-spell casting versions of those classes in CW, though I suspect that might actually WEAKEN the class...

[SurlySeraph]

I'd say it's perfectly fair to do this. It'll make them more powerful by giving them more options, but not by much.

[Toliudar]

Never played with the non-casting ranger or paladin, but swapping out feats and sneak attack will break neither the rogue nor the fighter.

[Mongoose87]

This would make getting into Blackguard less of a chore, not that it's worth it. Would you let a Blackguard do the swap, too?

[Ernir]

I'd say the rogue trading away the SA dice is getting the better deal here, but meh. It's hardly overpowering either way.