Fighters don't need the weapon or armor profs, and outside of thieves tools probably don't care about tool profs either (or languages mostly), but that's a pretty sexy feat for non-fighter types. A style and heavy armor prof is a nice haul IMO. If I were a fighter type I'd rather have an additional style and half an ASI.That’s fair. What about a feat that has a Fighting Style choice, and a choice of any 1 tool, weapon, armor, or language? Could be 1 tool, armor, or language, or 2 weapon profs?
Then it’d be useful to any class/build?
Maybe an additional actual skill wouldn't be out of place as the other half, or an option for it, if it were restricted to a sub-list of stuff that seemed suitably martial? (so not arcana or whatever). Survival, Animal Handling, Steath, Intimidation, that sort of thing.