"Arming" the ball over legs and hip rotation

[xFullCourtTenniSx]

So, if legs and trunk rotation are removed as such, what are his keep factors for creating spin, power, and such? Other thoughts?

A very strong arm. But if you removed everything generating power from the trunk down, you'd have a very weak shot (even with said strong arm, he'd have to change the shot drastically and couldn't have nearly that level of spin and pace together). There is so much work being done from the legs and core there. I think you're looking at the reverse forehand as being an arm only shot, which isn't true at the higher levels of play.

 

[zalive]

Ah! The superlative double standards of TTW experts

This is not arming the ball

But this is

Got it!

There's core rotation on both, no arming (Dolg doesn't use hips only to rotate, he uses lower back too, look how his shoulders rotate all the way to the contact).
But...for some reason you slow down the core rotation a lot prior to contact, so there's a bit of disconnection between the core and the arm at the contact...hips stop prior to contact, luckily there's still some lower back rotation through contact, then there's again more core rotation after the contact as your arm wraps around in follow through...so in your stroke the least use of core happens through contact.
If you compare the two, Dolg's shot looks more connected, the core with the arm.

Those clips from Dolg's BH were arming IMO, but he was out of position on both trying the best he could in a given situation, so those are simply not the right examples and definitely not the display of his technique.