You always need depth,
I agree but it's more important to have versatility than a host of players, many of whom won't end up playing. E.g. Great squad depth would be to have, say, Leighton Baines and Ashley Cole. However if one of them is going to play only 10-15% of games at best (as is the case with Clyne, him not being injury prone at all), what's the point? It's more effective to have versatile players that can fill in and be solid in those positions. If you look at a squad like United's (Ferguson being one of the greatest squad builders of all time) a lot of their backup players fill multiple roles rather than just one.
If we sign any fullback it needs to be one for the future, prepared to not play much this season and be available to step in when called upon, and as we already have a few of those, do we really need more?
