Streamlining character models

Hello everyone, I would like to ask about recommended approach to making multiple character models, that are able to use the same animations, basically how to recycle the first model as much as possible to make the next ones easier. In my case it is a WW2 game, so all the character models are human with the only difference being in face and clothes. Number of issues come in mind, for example offsets in animation - the hands holding a weapon could be off etc. What should I keep in mind when preparing to make the next character?

I sculpted the base clothing in mirror, then manually added some wrinkles to hide the symmetry. I plan to add the hands, head and combat equipment later on. But how will I make the next sculpt to work with the animations made on the first one? Am I doing this entirely wrong and is there a better way to go about it? Thanks for reading!