Mainentance issue: if the three groups work on different issues, it is pretty clear what to find in which wiki. if an xowiki instance is mounted within another xwiki instances, this looks to the user like three different subfolders. In such a situation, moving from a single wiki to n-wikis is a one-time situation, involving an export and an import - it does not need a programmer. altering the name to a name + folder prefix should be a no-brainer, but i have never used lors and i do not know, what carl uses in detail.
how many groups are there? about how many wiki pages are we talking?
one can certainly think about more clever solutions involving some programming - but for this i would need more detailed knowledge about the situation.
what means "while the learning module is active"?