Of course it was a tactic. A perfectly valid one, considering they only had a limited supply of thermal clips, and considering the conventional arms that they'd been able to source might've been less effective than outright punching the alien bastards.
Less fun in the long run too.
Letting out a distinctly unmanly shriek as Ash gunned down the alien who'd snuck up on him, Vega tried to hit the deck as the tell-tale red laser of a sniper danced over him. "They shoot me in the face, I'm gonna kill Vakarian..."