That's problem in order to advance IoM should take this kind of risk. On much lesser extent. So Russ and Legion Astartes are still out of their minds in this case, good to know. Some can blame Emperor for creating Horus, why i cannot blame RG for CA. It has nothing to do with IF. I am talking about him as Primarch allowing to AT using force against loyal Astartes. If we take RG and RD first one was ready to begin onslaught and kill loyal marines in order to force his CA, RD backed off only not to begin another war. And Astartes never had this kind of purpose. Prosperity of Ultramar is just retained from times of Imperium Secundus, so they just rich guys who can afford that. Why then ignoring of how Ultramarines left dozen of Imperial worlds defenceless to Tau(when Nids attacked) while ruling under CA? Or these worlds can be ignored? All of this was result of CA cause if Ultramarines had their Legion there Nids would have been problem. As i said RG is may least favorite loyal Primarch cause of CA. Still he is on my good side tho, good guys can make grave mistakes somethimes.