To be upfront, I am a wrestler, so that is the view point I am coming from.
I disagree with the notion that it is easier to take a guy down then to get up. In almost all levels of folkstyle wrestling, it is the wrestler who can keep his opponent down, after a take down, that wins.
There are many variables involved.
-top guy is LnP
-bottom guy is completely defensive, holding his opponent down
-top guy is wary of opponent subs, is outclassed and only wants sure things
-bottom guy doesn't to try an escape at risk of getting GnP
-opponents neutralize themselves, imagine that!
I also disagree that sub "attempts" deserve more credit. Usually they result in a small time periods of control and little to no damage. These time periods are usually less than the "worthless" take downs we often see, like against Chuck. His ass hits the mat and then he is back up. Now, if the sub attempt results in an escape, improvement of position, or better yet, damage, then yes, points baby.
This really is a complex issue. I don't think one could quantify it, but would rather have to give it the eye test. One can't simply use check marks on a paper and say Fighter A won because of this, this, and that.
Back to the whole notion that if there is a take down and then nothing is done with it, it should magically not count. One has to consider the control factor. It should be weighed similarly to that of aggression or cage control, but to a slightly higher degree.
Aghh, we could go on forever dissecting this. Just give it the eye test!