Currently, Sergeant Daniels doesn't issue any frag grenades to elite armsmen squads to make them rely more on their stealth skills, rather than scouting with frag grenades.<br/><br/>If you've got enough grenades for it, and there's nobody in the area you wouldn't mind killing, one of the best ways to get through an indoor area is to toss a grenade into every new room and around every corner, to dislodge defenders before you walk in.  As you noticed from Sarah, overwatches are DEADLY, though I imagine the group will be relying on flanking to get past the fixed defenders.