I had originally written this up as a reply to someone, but I thought it was good enough to post on its own.
My interpretation of breed types.
Atrox has lumbering patchy genetic engineering movement, an obvious breed of lower mental capacity and lower motor function due to the biological tinkering it has interfered with cerebral development, though much like terminators, their offensive capabilities are their selling point, higher targeting more effective damage dealt.
Opifex has enhanced biological strength from a living in a harsher environment then anyone else. Opifex have slightly enhanced body types better stamina then Solitus because the planetoid that the Opifex was likely developed on was a high gravity one. Which means their joints move less, but their strength is significantly enhanced. The only preferred body type the planet would support is small and short frames. Killing power almost on par with Atrox, however much less life and easier time equipping heavier gear/ weaponry.
Solitus have grown up on a standard planetoid resembling earth, are capable of carrying heavier weapons, but perform as effective with slightly higher average agility and average strength ( they are after all the human resembling breed) due to the weaker gravity then that of an Opifex planet the muscular structures aren't as developed as opifex, also they are much weaker then the biologically engineered Atrox. Which means they are the highest agility to achieve an endurance sprint.
Nanomage, a race that naturally is the lowest on both the endurance and stamina chart, a race with no desire for physical prowess, only the desire for pure knowledge and technology, it is naturally unable to equip heavy weapons, however enhanced nanites enable a comfortable offensive capability to the center of Atrox and Opifex, highest nano based defensive capabilities. However the lowest hp of all the breeds, and if defenses are countered the most easily destroyed.