I used to be sort of dazzled by the speed that a lot of kenpoists show on youtube clips. I thought, wow, those guys are really fast, blisteringly fast. I never clued into a lot of their stances.
Once I clued into the stances, I began to realize that many of these really fast guys have really lousy stances. Their feet are sliding all over the place. Feet are rolling up onto the sides, nothing is rooted on the ground, their feet are actually off the ground when delivering these techniques with blinding speed, they actually jump off the ground a little bit when striking something or when transitioning into the next strike, etc. This bleeds power and stability from the technique in all directions. It becomes dazzling speed with nothing behind it. A palace built on a sand dune.
I try to be tactful and not make personal attacks on people here in the forums, but I'll be honest and say that I've seen this kind of thing with some of our members here. I won't name names, but people here have posted their videos, and a lot of what I see, I think really is not very good. But people are proud of what they post.
I don't post my own stuff, so I don't comment about what other people post, at least not directly. But from what I've seen on youtube and whatnot, I think a lot of people who honesty believe they are really skilled, are actually really lacking. Much of it has to do with their stances.
Regarding the grappling issue that you mentioned, my kenpo teacher trained for a bit with the San Jose State University Judo team when he was young, after he had earned his kenpo shodan. When those guys would try and throw him, he would drop into a solid horse stance, and it became really really difficult for them to throw him down.
Stances go a long way in making everything a whole lot better.