Dark Side has 9 tracks. Bat out of Hell does have less. But neither are Neil and Tim and their (generally) 3-4 minute tracks. Would anyone here be happy with seven 3.5 minute tracks, taking up 24.5 minutes of a 70 minute CD?
Further.. If they're left with 15 still, that 15 presumably still fits on one CD.. Anyone want to pay for blank space?