Heavy Missiles were never OP. The only issue that Heavy Missiles ever had was that they were pretty much equally good at both close and long-range combat, to the point that Heavy Assault Missiles, which were notionally designed for short-range combat, were useless. The recent changes to Heavy Missiles have solidified their long range role, and given Heavy Assault Missiles a purpose again.

This is all that needs to be done with the Tactical Assault Rifle.

It doesn't need a damage reduction.

It doesn't need a recoil increase.

I'm not even sure it needs that much of an ROF decrease.

All it needs is an increase to hipfire spread to reduce it's viability in CQC, keeping it performing well in its role of mid-long range attack, while allowing the Standard and Breach ARs to have a place in the fight.