I know almost nothing about drumming. But to me, Charlie's underhand grip was noticeably unusual for a rock drummer.

Along comes Steve Jordan, and he is mixing grips. I've never noticed that. Thanks to Fake Fan videos: on SFM, 19th, PIB we can see that Jordan uses matching grip; on MR, MY, GS, JJF, SMU he uses underhand. (I had to look up the grip names on Wikipedia!)

Comments? I'm simply wondering "why."

While I loved Charlie, I agree with many others that Jordan has kicked up the Stones (saw them Sofi x2).

It sounds different. That's my guess.

Charlies entire posture distinguished him from most drummers. It made me realize I sort of resent the way they lean in or do those pumping motions. He never did that, it was all in his wrists

Looks to me like he is using traditional grip on pib and sfm and yes matching grip on 19th-

He has said that his goal was to get as close to the original recordings as possible and I guess he is using the grip that helps him with that. Vs Charlie that as far as I know stopped using matching grip in the late 60´s - which he only began to use because he had to play louder due to the screaming girls!!

He is doing a great job in my opinion, couldn´t have wished for more.