Weaver stance is, essentially, bladed. Feet about 45 degrees to the target. LAPD detective named Weaver was the proponent of this in the 60s...
Feet perpendicular to the direction of the target, arms equal, is called isosceles. This is the current thinking.
Prior to Weaver, the preferred stance was quite varied, but much was made of facing 90 degrees to the target (fully bladed) with the shooting arm straight out, to present as little target to he opponent as possible.
Regardless of stance, grip is important. The video was good, and essentially what I was taught in training.
High on the frame with the strong hand, firm, but not so tight as to lose fine motor control of your trigger finger. The placement of your support hand becomes the issue. I put the heel of my support hand in the gap left by my strong hand, wrap my support fingers around my strong fingers, and just leave my thumb parallel and forward of my strong thumb.
Basically, just what he shows in the video.
If you use your pistol defensively, then shooting strong hand only and support hand only is absolutely necessary. Principles remain the same, high on the frame. Firm. Wrist straight. Good control is more of a challenge with one hand shooting.