The Aethan Haht Garuud are an advanced race, haughty and insular, but generally peaceful. To humanity's surprise, it turned out it’s not because they can’t or won’t fight. They just don’t consider others a threat, and everyone else knew better than to bother them.
The base form of the Garuud is fairly delicate. They evolved on a low pressure, low gravity world. When they expanded into space, they realized that their form was poorly suited to both 0G and heavier gravity worlds. Their solution was to embrace biological and synthetic engineering. Body plans are dependent on career- starship crew are substantially different than terrestrial soldiers, which are very different from localized tech workers and scientists. This personal adaption led to a focus on biomedical science rather than ship and environmental technology (they never needed to develop artificial gravity or advanced radiation shielding for example). Even their ship cooling systems are designed more for the hardware performance limits than comfort of the crew.
Though the crew of the Garuud explorer vessel was fairly delicate (designed for heat tolerance, minimal life support, and 0G), Garuud ground soldiers were more akin to highly mobile tanks. A squad of Garuud could easily wipe out ten times as many human soldiers, even with vehicle support. Humans were forced to embrace heavy cybernetic modifications in order to provide any real resistance in ground attacks. Often, stopping a Garuud raid did almost as much collateral damage as the Garuud would have caused if left unchecked. During the Retribution War, their tactics tended toward a sudden blitz of overwhelming, strategic destruction, followed by more thorough cleanup of surviving resistance and infrastructure. They were more concerned with stomping on the anthill than making sure every single ant was killed.