sacrilege:
The concept it not per date. It’s at date #2 for the initial work, date #4 because that’s a barometer of it having been a real quality suggestion. If a girl gets to a few date #4’s she will married! To only do it at date #4 is missing the concept of “achievable result”. Date #4 is a bit far off when looking at the outset for a shadchan to focus on.
(in addition in many circles the shadcahn does spend hours with each side between dates advising coaching etc. but that should all be for a individual to decide what they think is appropriate recognition as per the effort of the shadchan for that particular shidduch.)
For the record this concept has been tried and proven