I think I would rather do something like:
If you spend a round studying an opponent, you can add your int modifier (in addition to your str/dex modifier) to your damage rolls for your next 2 attacks against that target.
I don't want to use the word "realism" because I don't actually care about "realism" in RPGs, especially Dungeons and Dragons, but the idea of applying your Int bonus to every damage roll is lacking in let's call it credibility. You make so many damage rolls it is absurd to rationalize a meaningful tactical decision (such as targeting a weak spot, etc) behind every one of them, and therefore it's very hard to buy that being smart will add to your damage rolls on EVERYTHING just like Dexterity does to your damage rolls with a rapier and Strength does with a mace. One of the things keeping the swords in the sword & sorcery genre for D&D is that physical stats still matter; magic is better/magic always wins is definitely a thing.
I think that would need to be a lot stronger, right now it's a bit of a trap option.
I added something to the fighter in both 4e and 5e that allows any mental attribute to be used as your initiative stat (call it battle ready).
I would like tactical maneuvers for the Battlemaster as the next step similar to how the Battlemaster has Charisma mods
I think I would rather do something like:
If you spend a round studying an opponent, you can add your int modifier (in addition to your str/dex modifier) to your damage rolls for your next 2 attacks against that target.
But by the same logic, with armor increasing AC and STR adding to bonus to hit, it's "absurd to rationalize powering through full armor on every one of them without any accuracy, and therefore it's very hard to buy that being strong will add to your attack rolls on EVERYTHING". No matter how accurate I am with a rapier that has no affect at all on my chance to attack with a longsword, and no matter how bad my aim and reflexes, as long as I throw hard enough my thrown javelin will connect.
While I have different reservations about it, STR only to hit is so unbelievable that some other ability that can credibly affect damage at least some of the time is way ahead of it.
Tactician
Once during your turn, when you take the Attack action, you can add your Intelligence modifier to your attack roll and damage when you attack with a weapon or make an unarmed strike.
I'll update the OP with this idea. Thoughts on the feat?
As there isn't a fighting style that boosts Initiative, I would be tempted for the Tactical Style to add INT to Initiative, as well as allow the character to choose to delay their action.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.