I'm not sure that I like the roles that have been defined by the company, for Mechs and other things.
I would say that the Hel / Loki Mk 2 is essentially a fire support mech vs brawler (on get close range). It's armor while not entirely as bad as the original version, it's certainly wouldn't last long in the brawl. At least to me anyways, however during the less Mechs era of the Dark Age. There pressing need to have star mates which could take up support such as Battle Armor and certainly Combat Vehicles designed get closer to shield less armored units.
Give the design was created with combined arms in mind, give clickytech game it came from was all that And Hell's Horses built thing initially exactly like that . I would think that could be a canon reason why it's not so armored and more about the guns.