[thejeff]

There's sort of a bug with mixed range/melee squads.
If you give a squad a 'fire' order, but the first unit in the squad doesn't have a range attack the whole squad will close to melee. This usually isn't a big deal, but it's really annoying when the first archer in your longbow squad loses an arm.

So, yes. A mixed squad of Humanbred and Fire Drakes would close, the Drakes starting to fire when they're within range, as long as a Drake is first in the list. Otherwise they'll just close and bite.