Yes Tony, you correct, the beginning adult crowd pile up the hours you state per month pretty quickly. These I speak of are getting 2x20 min lessons a week for each month for a total of 2.5ish hrs of coach training, but they tend to hit a couple hrs every day with each other encouraged by coach...so they average 40-50 hrs a month basically hitting the ball back and forth high speed to each other most of that time and practically nothing else. You right, they get real good at that real quick and bacically do not do anything else well, which is fine with coach at that point. These I speak of are adult players starting out, anywhere from young 20s to late 40s starting out. This is the crowd many coaches surprisingly give the power rocket setups to... but really, such a setup makes it very easy to do fast FH to FH at the table - the shot the coaches want this kind of player to use the most.
Sometimes, you see a parent bring in a kid for pro-coaching, but you do not see the kid play in the club.
The kids identified as school athletes are ID'd around 8-9 yrs old, the school hires an ex-pro to be a drill SGT going apeshyt on these kids hardcore boot camp doing mostly the most fundamental stuff - FH to FH, BH-BH, serves, serve receive, mid-distance loop to loop or hit to hit with some practice matches. This is 5x a week for 3-4 hrs a day in the school's multi-purpose room now turned into a pro TT camp. That also quickly adds up. Those coaches usually go kinda conservative early on for equipment and later hand them something more offensive.