Model for Investment in GP Platform

Does anyone have a good resource for understanding the economics behind investing into a sponsor? Or even just a model template to share?

I'm in position to lead an investment into a RE sponsor who's assets & focus co-locates well with my firm's; structure would look more like an acquisition & merging of resources rather than a passive investment. Obviously fee revenue and carried interest are driving any inherent value to the business, but am having a hard time wrapping my arms around a more thorough analysis of the economics. It's early enough in the process that hiring an advisor isn't yet warranted. Appreciate any help.