I would just have .the feats trade disadvantage on the attack roll for advantage on the damage roll. Just roll damage twice, keeping the highest roll.
this is a problem that stems from two issues. The first one is ambiguity in the RAW, the second one is lack of defensive gear. The first problem is easily addressed by active DMs who make sounds judgement calls where the rules are unclear. the second problem is easily fixed by adding new shields and splitting them into two categories.
Light Shields
Targe - This small shield is strapped to the forearm, allowing the hand to remain free. Gives +2 AC if proficient. -4 ATK to bonus attacks and 2H weapon attacks
Buckler - this light shield offers protection without hindering maneuverability. +4 AC if Proficient
Heavy Shields
Tower Shield - Prerequisite 18 STR.
+6 AC
spend reaction to for total cover.
Disadvantage on DEX saves
this is a start. feel free to add to the list if you think of a good one
The base shield is only +2. Making two smaller lighter shields that allow use of hands AND higher AC bonus is a bit extreme.
I'd add two new shields;
Buckler - +1 AC allows two weapon fighting or defensive bonus per round.
Tower - +4 AC with a 15 STR, reduces movement by 5
I am not sure if anybody noticed, but rogues actually have the highest non-magical damage potential
No they don't, no magic items and no spells a fighter still does more damage.
Fighter - Great Weapon Fighting style - great weapon master (feat)
That is 4 attacks doing 2d6+5+10 each (8d6+20+40) min 68, average 88, max 108.
Compared to 1 attack from a rogue using sharpshooter(feat) that is doing d8+5+10+10d6(sneak attack) min 26, average 55, max 83.
We could change things up and use bonus actions for an extra attack each, but the rogue can only sneak once, or talk critical hits but the fighter will get more of them so even accounting for the doubling of all those sneak attack dice the frequency of the fighters criticals will pull it ahead especially if champion. I didn't go with battlemaster that would add extra damage for the fighter too.
The rogue hits big once and it seems amazing, but the fighter makes many more attacks.
And everything that does buff attack damage like magic helps the fighter more because they make more attacks.