Collection with repeating requests

I need some advice on how to organize my collection. The thing is that the system I’m testing has such business logic that I need repeating requests with a small delta at the end.

Scenario 1: Request 1, Request 2
Scenario 2: Request 1, Request 2, Request 3
Scenario 3: Request 1, Request 2, Request 3, Request 4 etc.

How to optimize such a case without copying the requests? Right now I have a collection, with a folder structure in it. Folders are named Scenario 1, Scenario 2 etc. In those folders are requests, and as you can see it involves a lot of copy and pasting. The upside is that I can easily execute the folder I need using collection runner or newman, but the downside is if Request 1 changes, I need to update it to 15 or more places

How to tackle and organize this to avoid this much copy-pasting?