We are fuked either way because Asa is an average winback, he offers great covering and stamina but zero consistency in offense.
Evra seems to be past his prime and is unreliable for some reason
Asamoah is an amazing wingback.
The profile of this position is basically impossible to satisfy in every single aspect, you'd have to be excellent in both defending, crossing, dribbling, creativity, huge stamina,...
In other terms, you'd have to be a beast defender and flashy winger in one, not to forget being able to run for 90 minutes straight.
Asamoah fullfills most of these criteria perfectly, of course lacking in others as well, but that's to be expected.
Evra on the other hand seems to be a rather mediocre wingback to me.