I'm sure this subject has been done to death before, but humour me, because i am a thickie about this stuff.
Suppose a person is a member of 2 clubs- one affiliated for fell only, and one affiliated for road/track/xc but not affiliated for fell. They presumably are running first claim for either club depending on the surface. Can they then join a 3rd club, affiliated for everything and run 2nd claim for that club on any surface, as long as they are not required as team member for their first claim club?