You can land a P-3 from either seat; there's just not a really good reason to do a right seat landing, especially with a mission aircraft, other than proficiency. We learn in the left seat, then do a right seat syllabus prior to aircraft commander. Other than for letting junior guys take reps, if I was signing for it, I was taking off and probably landing from the left seat, as that's where the nose wheel steering is. I always considered that my last ditch chance to keep it on the runway if things went really sideways.
I'm one of those left seat sitters who flies with his right hand, swaps if I need to adjust power, and goes back to flying with his right hand with the exception of on final/in the flare. T-6ism carryovers, I assume, because I used to be an ambidextrous pilot. I got scolded for it at VP-30, so I played nice, did it their way, and then went back to flying my way as soon as I left that swamp (again).
Any kind of EP with enough pilots on board to do a seat swap, and the AC should be taking the landing from the left seat (unless he's a dumbass, then all bets are off).