As you're talking about 3 or more figures, then you're not talking about a close-up render but a wider scene.  In this situation the solution suggested by bantha is a good one.  There are likely to be 6 large textures associated with human figures (assuming one for the head and one for the body) plus you may have equally large textures for the clothes (which may cover the body skin texture anyway).

There's a tutorial here that explains the process.

Vue is a worthy upgrade (I've got P7 and Vue Esprit) but you're still going to have a potential memory problem whichever program is used for rendering with the amount of data being handled.