If the FO doesn't have any chance to T/O or land the aircraft..... what difference will there be( in terms of the F/O handling ability) after sitting on the right seat for 5 years without any handling sectors?
you can't just learn handling by watching.
on rare occasions where the captain F*** up, will the FO notices it early enough? if the FO does notice the problem(no flare, short flare, long flare.., pilot incap at 50ft agl.. etc..etc..), does he know how to Take Over? even if he manages to perform a GA, can he bring the aircraft safely back on the ground?