accuracy only influence the chance of ships to hit capital ships, fighters and bombers and is set as 100% to capital ships.
The buff helps fighters and flaks attack bombers/fighters or helps in the case of a few select things in the game which reduce the accuracy of a fleet against capitals/fighters/bombers.
To me the best use for this is to have ships that aren't meant to hit strike craft have a chance to hit them, and usually if a capital ship can hit a strike craft it could kill it in one to 2 shots, where if not it might hit once out of 10 shots and give it plenty of time to regen.
It doesnt make non anti-strike craft able to attack strikecraft, they cannot fire at all at strike-craft.