@Eggs has nailed it early doors....not bothered about system, only bothered about effectiveness.
I would always go three at the back with wing backs, but yeah you need the correct personal to implement it properly.I'm coming round to the three at the back as a system. I think it's the future. Everyone will be doing it in 5 years.
Unfortunately our centre backs are pretty woeful but it gives scope to allow our more naturally attacking players scope to actually go forward.