I'd say to put everything into a single 1024x1024 maps, which should be enough for almost any fighter, this way you won't have any doubts:p
BUT personally, I'd go in that situation for 2 1024 rather than a single 2048
it is true that the more textures the more passages, but with 2x1024x24bit you save around 10 mb compared to 1x2048 if I'm not wrong, which doesn't sound that few to me, talking of just a fighter. I may be wrong but to a common sense I'd say that gpu's calculation power grow more than gpu's memory in perspective, and that if you drain the memory, you slow down the calculation time too; it's not a problem if it happen for a single model, but if you do it regulary I dunno what could be the result. I'm thinking at how the high res packs for fso can be intense even for non old PCs, sometimes. Well I'm curious to see what bob will say