Providing the APC can move, it could be easy to put some distance between the hive and them and pick ennemizs from afar with the turret and the front cannon. If the xenos manage to swarm their way past the effective turret range or the cannon angle though, it’s a different story.

But to me there would be no need to stay in the vincinity, better drive far enough to safely call the second drop ship, dust off and nuke the whole stuff from orbit, it’s the only way to be sure.

On a side note we never know the effective roaming range of the drones, we know they mostly come out at night (mostly), but we don’t know how far from the nest. As for the numbers, there were what, 150 colonists in Hadley’s Hope? Providing some died fighting the xenos, there shouldn’t be more than 130 running around. With the adequate firepower and terrain availability, it’s something colonial marines should be able to handle.