You forgot Borough as in Stevenage Borough.
Aston is a place - the football club is Aston Villa. Villa is the secondary name.
Port is not a place - the club play in Burslem and although Port Vale is not a real place the club is Port Vale. Vale is not the secondary name.
Crystal is not a place - Crystal Palace is a place in London and the club has no secondary name.
Still think of Stevenage as Borough (my team Barrow beat them in the FA Trophy Final in 2010) - agree they have now dropped the Borough bit.
How about secondary prefixes? AFC Wimbledon for instance ? Maybe not!
to conclude, great quiz.