If they were mod crew yes, you could hit the cap with 2-3. That means 500-600+ vets at lvl 120. But then, there is a high chance your account would be banned for it.
Or, if you were hardcore to power level IJN gunners, BO, engineers, scout in order to turn them into soft support, in a legit manner. Then yes, you could hit the repair cap with 2-3 repairman with an monstruous high ammount of vets at lvl 120.
You won't hit the repair cap with 3 repair especially for IJN.