BF2 Map Sizes

[[RNGD]Tyrant]

I was under the impression that with BF2 you could choose your map size and
your total players separately. But the Server launcher does not seem to
allow this. The info field for the maxPlayers setting says: "this setting
also determines whether the 16, 32, or 64 player configuration of maps is
used"

Couple questions:
1. how does the launcher choose which map if you don't pick 16, 32 or 64?.
For example what if you set your server to 48  players...does it choose 32
or 64? 
2. is there a way to 'delink' these things to allow (for example ) 16
players max on a 64 player map?