Of course it was not a feasible choice but just an outburst of anger.
However harsh the Imperium treated the miscellaneous troops from the remote worlds, they would never betray them to the Covenant Alliance, because the price of joining the Covenant Alliance was to give up all their feelings and the dominance of their self-will, which would be more miserable than killing them.
Besides, there were only different roles within the Covenant Alliance that did not have a hierarchy. They called each other "brothers" and "sisters" and regarded themselves as "lambs, tools, and missionaries of the gods". Even the super experts who were capable of turning the world upside down would be equal to the weaklings who could not catch a chicken.
