If you turn off 2 ADRs you will lose Flight directors, Autopilot and autothrust.
If you turn off 1&3 you will need to manually extend the gear and will be in direct law for remainder of the flight once gear down, gear will not come up on a go around.
If you have no prior ADR failure turning off 2&3 would surely be a sensible course of action to allow the capt to become PF for the upcoming alternate law raw data man thrust approach to direct law approach, landing and possible go around. Not saying FOs wont be able to, but personally I would prefer to take that on.