As I’ve noted before, so much of the grappling instructional content we’ve seen in recent years has focused on taking one element or aspect of grappling, and expanding small systems around it. It’s worked well, with improvements in many aspects for anyone to have a more complete game.
Some approaches work better than others, and some instructionals are more useful on a day to day basis for the majority of grapplers. For example, I’ve recommended the D’Arce Killer DVD in the past, but note specifically that it is quite niche and perhaps more suited for somewhat advanced practitioners, as good as it is.