I doubt it would work this way. One of the C4C guys, Renan Ozturk works with Sherpas, I think. Kind of like he's part of both. I would assume that it is just a cooperation between Sherpas and C4C, not that Sherpas pays them.
to the above comments- C4C and Sherpas have collaborated on a number of different projects over the past few years. Sherpas doesn't 'pay them to make their films'. Think of it as freelance/contracted work for C4C. It would be the same as Sherpas or C4C hiring on any other outside filmer to use their set of skills. They are all friends within the same filming community ya know?