Well Test matches are classed as First Class games so they can be included in the FC most wickets in a season. However, the example you have given, of a player who is playing outside England, I wouldn't allow that as a record. Because 'you' haven't controlled those other matches. To keep a consistency with that, I would only allow a player with say 60 test wickets and 120 fc wickets, if you had control of both sides. Say, Durham and England if Harmison took 50 test wickets and 60 FC wickets. I hope that isn't too confusing. I had to think about that one!