Well let me just say, that “workflows” can vary from artist to artist. There is no one way to do it. If you interview several artist about their work, they may all tell you several different workflows they used to produce there work. So, there is no wrong way to do it. It really comes down to the tools available to you and what you are most comfortable doing.
In my opinion (just one of many) concerning character development, you don’t really need to prep a base mesh in a subdivision modeling program (like Maya) if you are going to be sculpting. Zbrush and Mudbox can handle creating a base mesh pretty well these days. I can’t comment on Mudbox in detail, but you can use Zbrush’s Z spheres to “block” out a base mesh. Zbrush a lone can also handle retopology. It is a one stop shop. It’s also a heck of a lot cheaper than Autodesk software. It does however, have a higher learning curve.