Stop being analitical!

[nablator]

The question for the VMS is therefore why did words occur together with similar ones?

A possibility is that Voynichese uses a very flexible system (whatever it is), locally made less flexible (on the scope of one or several quires or pages or even a few lines) by variable self-imposed constraints that favor (or restrict the usage of) some combinations of glyphs, thereby creating recognizable "styles" or "languages" or "types" (René Z.) of words. Other local similarities may be explainable simply by convenience, because reusing a familiar subsystem or tactic (as in a one-player game) is easier than inventing a new one.