User blog comment:RemosPendragon/Questions to ask/@comment-33731050-20150226212728/@comment-24909831-20150227145617

And I would take anything related to rank "Lord Solar" (or in fact "Lord Commander Solar") with as much salt as possible. There is no given fact that this Warmaster Macharius was "Lord Commander of Segmentum Solar" making title Lord Commander Solar, Lord Solar in short, some other title within the Imperial Guard hierarchy. Macharius also inherited that title and I, at least, have lived in understanding Lord Commander is chosen within the Imperial Guard. Macharius was also noted to be only the second Lord Commander Solar. Lord Solar has absolutely nothing in common with titles "Lord Commander" (of Segmentum) or "Warmaster".

That is nothing but couple missourced facts on wiki sites that have begun to be canon as so many blindly believe whatever is written on wiki sites.