Pay Referral Fee to Architect as a General Contractor???

[Guido Canedo Flores]

Hello BP! first time poster here. Has any Builder/GC here ever payed a "referral fee" to an architect for bringing you a custom home project? My company has been doing residential Spec builds in Austin for the past 6 years or so and recently got into doing Custom builds, an architect we have worked with in the past approached us and basically he wants us to build a house he's already designed for his clients, (we are still in the process of meeting with them and doing estimates etc.), we verbally agreed on a 20% GC fee over construction costs, but I have a feeling he will want to split this 20% fee with us somehow as he tried to do something similar a few years ago in a project that didnt end up happening (he wanted to split the 20% in half between us) which we didnt think that agreement was fair at the time. I would not be opposed to give him a reasonable "finder's/referral fee" for bringing us business and introducing us to these clients, but I've never done something like this before so is there a reasonable number that people have done before? Or is this a no-go in the first place?