The mental side is easier at hooker because you have to make less decisions, but if you can't defend then the big boys will trample you, sucking the defence inwards and then your centres/wingers really do have no chance.
The reason halves get moved to the centres is because they want to either avoid the standard giant second rower targeting the half to wear him out or their defensive structure attempts to cut the attacking movement down before the centre gets an opportunity to go one on one with the half.
They never go as far out as wing (unless Sheens is your coach protecting lovechild Benji) is because of the different attacking kicking options a half isn't equipped to deal with.
Long story short - a shit defender is a liability in any team regardless of where you put them. One side tries to exploit it, the other tries to limit the damage.
