I know your response wasn't to me, but I will admit that I know VERY little about striking, although I have some limited experience. In the spirit of your response above, would you be willing to consider that you have made statements which show how little you know of grappling?
Here's basically what I know and what I don't about grappling;
What I know little of - BJJ grappling, Sport grappling, the low mount is relatively new to me (more used to somewhere between high and low mount) but I will be working on that soon.
What I know a bit about - multitudes of joint locks and breaks and escapes from holds, a few throws, defense of takedowns, takedowns, leg sweeps and trips and how to stop someone for getting on top of me (have done that in a real situation once, got neither mounted nor hit) and how to get up after being knocked down, like in the video of the technical standup (have done that in a real situation too), although the last 4 were not technically grappling per se.
All of the grappling that I have learned is from the standpoint of self defence, trying to avoid being on the ground in the first place and getting up before anything bad happens once I am there. Putting someone in a joint lock to persuade them from attacking me further and being ready to increase the pressure or break that joint if they resist, or if necessary to just break the joint straight away. The mount defence is not taught with a competent grappler in mind, just the average thug who wants to sit on your chest/stomach with his hands around your neck trying to squeeze your head off or punch you in the face. Now I am not entirely sure (that's why I said
possible) how the striking and blocking will work during the high mount (I will have to test it out sometime) but it works just fine from the lower position. Now if I was ever to be attacked by someone I knew to be a BJJ guy I would do everything in my power to keep him from getting a hold of me to put me in any kind of mount because if he did he would have the advantage and that's just not acceptable.
It is a little difficult coming up with possibilities and/or conveying knowledge on unfamiliar positions based on one 2 dimensional representation of the top of your head, you really need to see them in 4 dimensions, but coming up with things on the fly is a very important skill to have.