Haimy:
You wrote: “An experienced shadchan can be very helpful at this stage.” Alert!
This “experienced shadchan” needs NOT to be the one behind this shidduch. There is an inherent bias, that upon the sealing of the shidduch, there is a money transaction. An uninterested third party has the luxury of being able to be more objective. I have observed quite a few shadchanim engage in frank lies in order to pad their pocket (sometimes other motives, not always money). A shadchan may and should charge for their services. And we have all heard the famous quite (I saw it stated by Ran Yaakov Emdin) that שדכן is ראשי תיבות for שקר דובר כסף נוטל. But to force a shidduch to completion with the wrong bases for doing so is unfair, perhaps even criminal.