I'm all for a great running game and there are situations where Jeanty makes sense at #9. But, I'm not sure Rattler is really a guy you want running the Read Option. He's more athletic in the Mahomes mode rather than a guy that can really run like Hurts.
Anyway, if Jeanty is BPA then you take him or trade down, but I don't see why people are so dead set on him as BPA at #9. Lots of testing and evaluations left before boards are stacked. And we don't even know who our HC is or what system will be run on either side of the ball so that can change how the board is stacked for the Saints.