MEP and Real Estate Firms

Lets say you have a real estate firm that employs a hundred "independent brokers" who are all paid via 1099 Forms.  The real estate firm itself has several W-2 employees, primarily the owners and clerical people.  My question is could the real estate firm adopt a plan that excludes the independent brokers, but does cover all of the W-2 Employees and the owners who are primarily paid via K1 under an LLC?  Assuming that is possible, could the real estate firm then offer to the independent brokers the ability to adopt their plan, but under terms of a multiple employer firm.  To clarify, each independent broker would be considered a separate firm that chooses to adopt the plan for the employees of the "independent broker's firm"?  This would be similar to a MEP that covers several independent franchises where there is no common ownership, making this to not be a controlled group.  I am guessing that problems might be due to Affiliated Service Group Rules and/or the independent broker being deemed employees of the real estate firm.  I understand that the key to this topic is proving that the "1099 employee" is truly an independent contractor, including the ability to control work hours and work location; and that a Form SS-8 can be filed where the IRS determines if the person is truly independent, or if that person must be treated as a W-2 employee for issues like benefit coverage.  Any and all comments are greatly appreciated.  Thanks in advance!!!

Who wants to herd a hundred cats, I mean, sole proprietorships?

You might be surprised by how easy it can be.  The key is establish solid "information paths" before doing anything.