This. It is a cardinal sin to assume that everyone who is effective is drawing from one wellspring. I feel that I have encountered multiple distinct sources of internal skills. Hell some of the sources I am working with have strategies so different from those described on Aikiweb that they do not even generate power. The people I have encountered with working skills are pulling from one or more of these sources, and undoubtedly from areas that I have yet to begin to penetrate. A lot of the people who are currently dabbling in these areas assume that the high level abilities are an individual's expression of a single skill, and worse, they assume that when they encounter someone who has working skills, those skills must be rooted in the same concepts they themselves are already practicing. Keeping one's mind open to the idea that you may not already be on the right track, that you may not even have a clue yet as to how someone's skills work, is the only way to create enough space in your practice to actually get traction in a new system. Of course time spent with anyone with working skills will help you get traction with other working systems, but please do not assume that they are definitely doing your stuff.
This is a good discussion to drill into . . George, I'd be curious as to your take around Ushiro's energy, energy level, energy "stuff" that Ikeda is doing - especially where it's different from what you've observed Mike and Dan to be doing. My default hypothesis is that there's one set of skills with different levels and spins, but am not married to it in light of better information.
Ben, along those lines, what have you experienced directly that leads you to posit that there's different skills altogether? (again, levels and emphasis is one thing . . akin to Judo & Wrestling both being grappling) Comparisons?