You could also just create a number of tiddlers that tag to the one you want different versions of and add the Author at the end, e.g.:
SomeTiddler
SomeTiddler (Fred) ...tagged SomeTiddler
SomeTiddler (Eric) ...tagged SomeTiddler
But then, merging anything back into the main tiddler may become more and more difficult. However, if you keep a tiddlers scope (=content / length / # of topics) at bay then this may well be a managable workflow.
Cheers, Tobias.