It's difficult to picture what SISU's role would be in any "partnership". What would they bring to the table ? The Byng group would bring investment, they would be dealing with ACL/Council/Higgs re stadium matters, they would provide the CEO (surely Fisher would go?). But SISU ? Maybe it's some way to give them an exit strategy and avoid any legal battles ?
I am not sure, though, whether ACL etc would work with a set up that includes SISU. Surely, they have thought of this ?