Three of us presently share an aircraft and often there are at least 2 of us onboard if we're going any distance. Flying leg and leg about is fine, but its surprising how often it 'helps' that either of us can fly and/or land the aircraft.#
Of the 3 of us, I can fly from the right without any issues - different types in the past gave me a huge head start. One of my pals can do it - but is not very comfortable at it. The other - it's a life or death issue for him to fly from the right....
Do n't know why - I suspect some people learn how to land and can only use those movements with those limbs in that situation.
End result - I sit on the right most of the time!
And no the POH says nothing about the where the PIC sits.