While I doubt most people have sufficient "objective statistics" to truly remove ego from the equation, there's a middleground here.
Write up your detailed proposal as typical, but before you click send, put an "executive summary" at the top, with maybe two sentences. One to describe the problem and one to describe the solution. You can put all the detail you want in the rest of the document. But the onus remains on you the engineer to make a recommendation, not just list options. If you genuinely believe yourself to be a probabilities it should be easy!
Write up your detailed proposal as typical, but before you click send, put an "executive summary" at the top, with maybe two sentences. One to describe the problem and one to describe the solution. You can put all the detail you want in the rest of the document. But the onus remains on you the engineer to make a recommendation, not just list options. If you genuinely believe yourself to be a probabilities it should be easy!