Sand Eaters don't get enough respect. Long deployment in an extremely high attrition environment. Dust Giants may reinforce them at key points, the Blind Legion gets the Vex recon missions, and the Seige Dancers represent the heavy hitting armor of the Cabal force on Mars. Skyburners engaged in forward readiness and quick response in system. Intel/exploitation units like the Ice Reapers in specialized environments. But it's the Sand Eaters on the long patrols, over-watching positions under constant probe.