Lines of defense in wrestling
1) head
2) hands/arms
3) hips
4) legs/feet
Against Woolley demian couldn't get past his hips and Woolley was using them heavy to stop the shot
Colby was using a combo of his hips, less offensively, and his footwork to really hinder Maia to get any real momentum after penetration. I teach my middle schoolers to do the same thing.
The thing with Woodley is that he was doing all the right 'first moves':
1. Punch with the hips/hip thrust to meet the shot with impact
2. Jam the outside underhook in to lift up, and
3. Block the inside arm to stop the change off to the double
In this situation, someone deeper in wrestling would either, go to the crack down, go out the back door, or beat feet and turn the corner.
John Smith had a pretty good single leg, you might hear, but his high crotches rarely ever went on 'without a hitch', and he scored most of his points with these three methods.
Another thing is that there were a few times Maia did get Tyrun's leg pulled out, but tunnel visioned on running the pipe (like a lot of guys who take a more 'supplementary' perspective to learning takedowns, to a lesser or greater degree), which is a stalemate against guys with good balance until it ends with them wriggling out/getting the underhook in.
In this situation, the strongest single leg finish there is is bringing the leg up into the treetop.
Another more mma specific example would be Ben Askren, who uses his shot more like a greco high dive, to get a waistlock/double underhooks to come up and wrestle them down.
And of course there is the cage itself, which makes attacking the legs harder, but upper body takedowns easier. This is another area where Maia's tunnel vision on the single leg cost him, which was doubly frustrating because he, himself, had shown good clinch takedowns against the cage in the past (particularly with a move i personally call 'The Broomstick').
Which bears formal similarities with the classic over/under step around attack (eg; metzger, kosoto gaki, et cetera).
Another great one is the underhook throw by.
Which is very similar to how Yazdani uses the underhook, by driving at a critical angle, obliging the opponent to either, just let him throw him by, or try to keep his chest in, whereupon he hits the knee tap, or try to whizzer hard, where he'll finish by shelfing the leg or stepping around.
Eg:
Pushing your opponent around is great since, if you're moving him, he has no base to strike you with, while you're in position to strike him (and if you end up against the cage, all the better).
The slideby is a great untapped resource for the clinch in mma i think, since, a collar tie+bicep tie is the classic strong position for throwing knees, or just the collar tie alone for short uppercuts, which opens up the opportunity to attack the back angle with the merkel.
(throw by here but same substantial principle)
There are a lot of interesting nuances in attacking the legs, and many of the same techniques can also pull double duty as methods of sweeping as well. I think on balance though, it pays to focus the most on upper body work for mma, as it translates better to strong clinch fighting (something which many fighters, even many with wresting backgrounds, have weakness in).