Most of them can change sides pretty easily, but many of them will be far more effective on one side than the other.
Loko has a brutal right hand fend, to the point where I don't think I've ever seen him carry the ball in his right. He's also got that footwork to get him on the outside (left) of his man - most players can't do that to both sides of a defender.
One player who can step off either foot is Willie Tonga, but he's played just about every game in his career at left centre, so he's bound to be better there than on the right.
In saying that someone like Tate was very good at getting outside his player on the right hand side and was a very good out of dumby half on the left for the same reason, so while there is an advantage on one side of the field a good player will be capable of adapting that to the other side. Loko is a left centre and a pretty good one at that but if W.Tonga does come here he will have to adapt and you would think he would be capable of doing that. I personally thin Esi Tonga would find it easier to adapt to the right then Loko but I personally would much prefer Loko in the centres above Esi.
SK might just be getting the best squad he can and working his team out later, I doubt any one here would reject the likes of Willie or Esi Tonga, Lafi or Linnett after some of the performances we have seen from our edge players.
And as for converting a centre to the wing, it's not that easy, especially if he's never played there much - defending kicks is such an important part of the game and requires good awareness and decision-making, which isn't going to come just because a guy is big and fast. It's generally easier to convert a fullback.
That said, if I was going to convert any of them it would be Loko.
I have to disagree here, IMO fullback is much more difficult to adapt to then the wing. Most players that come through the grades and initially play on the wing are done so before being trust into the centres or fullback.
The wing is generally pretty simple to defend if you have half a football brain, it is just that any error you make is generally exacerbated by that fact that the opposition is very likely to score. Often a winger will be chastised for his inside men making poor defensive plays but generally speaking it is a much easier position to defend then fullback or centre.
