The wider hanmi he used then were standard, more or less, for the Aikikai. Then the stance started to become narrower and yes, to my knowledge, that is not at all common, outside of the Iwama lineage. (I tried to adopt it in a Hitohiro Saito seminar and it made my lower back ache.) You would disagree?
Well, there are more Iwama lineage than Saito Hitohiro.