Hello,
you can have as many workflows in Alfresco as you want - either by implementing statically different workflows or having a workflow interpret a parameter and automatically skip some of the (non applicable) steps. You have a full Activiti engine at your hands in Alfresco. I know some systems are indeed limited in how many workflows can be associated to a single piece / type of content (I have seen that allow at most one statically associated workflow for a type), but Alfresco / Activiti is not such a system.
Regards
Axel