There are two reasons why this isn't generally a problem.

Firstly, because collaboration occurs only between small groups within the broader PowerHouse community.  Your professionals will choose who they deal with and what level of interaction they have with others, deciding which member-issues they contribute to solving, and choosing who they ‘invite’ to help with their own issues.  Selective interaction makes it easy to minimise the effect of any personality clashes. 

Secondly, failing this, it is usually possible to swap to an alternate PowerHouse entirely.