Junior is consistently shown to be old school. Even in the 60s, as a young man, he dressed like an old school 40s-50s gangster, whereas Johnny was a modern day hustler who was like a criminal Dean Martin. I think Junior grew up idolizing all the old guys and felt they were what a gangster should be. Johnny was more of a "modern" (for the 60s) guy like Phil Leotardo and honestly, probably less intelligent than Junior. I look at as Johnny was the brawn, Junior was the brains; they made an almost undefeatable duo as such. There's a reason Johnny took Junior along on his collections. Junior was old school even in his prime and I think Johnny respected his mind, even if he was beneath Johnny in the pecking order.