It turned out there was a reason. A really good reason for that. The mercenaries had been unable to contact any Vexical government or military installation that was still standing. So they had taken up to helping civilians on their own. Eventually the foreign militaries had taken notice and unanimously agreed that local mercenaries were kill-on-sight.
Now they had been divided and had split up into several locations with a mix of groups. All of which were centered around protecting a group of civilians. This group was one such set of mercenaries.
Apparently the only reason they were not being attacked was that they were near an area of contention between three groups. So the enemy was being careful about attacking a fortress for too long since it would expose their backs to their enemies. Fortunately it appears the tower had its anti-air defenses as well. While the civilians were the only thing that was likely keeping them from doing a planetary strike.
