Any poptype above 87 will result in no recruitables.
The way it works is that on game creation, defenders are randomly assigned according to the radnomly determined poptype. THEN, map file is parsed, and #poptype commands overwrite the random poptype but defenders stay.
There was a thread a couple of months ago around the time the Magic Site DB came out where map scripting was discussed and I posted it there. Looks like you missed it then.
