I’ll break your question into two parts: distribution and notification.
If you’re getting push back that there aren’t enough, I suppose that’s a good thing. Either your raters are setting the bar unreasonably high, or you really do have a talent shortage. I find it’s usually the later, and it should be a wake-up call to get moving on development. You’ll need to take a look at those in nearby quadrants and start doing some serious development, and start upgrading your talent though external hiring.
Perhaps the more important question is “what are the future needs of the organization and do we have enough talent in the pipeline to fill those needs?” For example, if an organization is projecting a need for 20 new sales managers per year in order to expand into a new market, then ideally you’d want 2-3 candidates to choose from for each open position. That would mean that in any year, you’re actively developing 40-60 candidates to get them ready for these opportunities.