"Discuss what you want, but I guarantee you wont get any closer to hitting the backhand like the guys you are studying. If you want to get better you need to see the big picture, which you continue to ignore. "
I'm not going to get better ... I am a 61 year old ex-4.5 singles tournament player ... I only get worse from here.
But that reminds me ... would my past 4.5 singles state ranking, or my number of 4.5 tournament wins have anything to do with my observations on strokes here being valid or not? I would say no ... unless I was talking about tactics, and then I would say yes.
Players learn differently, some or more technical than others. I never once discussed strokes for 40 years before here, and did quite well. I know what wins, and what doesn't ... and it's not how pretty the strokes are. It's also not how well you do in drill with your coach.
Yeah ... have to disagree on the ball machine. It was priceless learning the 2hbh stroke for me. No one would think that was all you needed to develop a match-ready stroke... but those initial thousands of reps was priceless.
One last point ... my guess is most would not end up with a straight left arm at contact on 2hbhs unless you consciously learned it that way. If you don't think arm positions at contact matter, than no worries ... never need to care. I wanted a left arm straight at contact going in ... so I learned it that way.
Good luck ... hope you have a great tennis career.