I think we agree.
Blowing into a leadpipe, like Greg show us, is much better in the beginning.
Tine Thing Helseth was one example of a player who had a professional teacher from the start. When she now demonstrates mouthpiece playing you can see that she just blow air and when the rim contacts the lips, a nice sound comes out of the her mouthpiece. (It is on YT somewhere)

Arnold Jacobs wanted you to “translate” the “song in your head” into the mouthpiece.
Both he and Herseth had a very good sound when buzzing the mouthpiece. I heard Herseth demonstrate his mouthpiece playing once.
Btw, Jacobs did not like lip buzzing, but he would allow a few of his students, like Gail Williams (horn player in CSO) to do that. On the other hand if you had a rim you could buzz that.