User blog comment:WarpSpawn/(DAT): 20 Primarchs, 18 Legions?/@comment-25033299-20111025215423/@comment-1932673-20111025222027

Yes really, if two legions were never founded because their primarchs weren't found then that means that the Emperor only intended to found legions once he had recovered that legions respective primarch. Well thats the implication of what you just said.