I prefer not even using terms like "drop and drive" or "tall and fall".
If you need a simple definition of what I would call drop and drive, it would be to collapse the leg as you are moving forward. Driving the hips and body as you are rotating into footplant.
People define what they see all kinds of different things, that's why I feel it's always a mistake to pigeon hole the throwing process with these terms.
But if you look at Zumaya, he is clearly doing what I describe. Seavers mechanics are similar to Nolan Ryans. I think all hard throwing "pitchers" look generally the same at certain points in their delivery.
It's all about loading your body, generating momentum, and transfering that momentum into your throwing arm, in an explosive manner.
Like a whip.
I could really care less about what the "organizations" will let their prospects do. Most time if a guy throws hard, and can throw strikes they leave it alone. Doesn't matter what "style" they have.
So if you want to tell the masses that "drop and drive" is bad, and "tall and fall" is the only way to throw, or only throw "drop and drive" and scrap "tall and fall"...go ahead....
How 'bout "tall and drive"(TM)
Like I said....buyer beware