The Saints best WRs with Payton were not high round picks outside of MT who was a 2nd round pick later in Payton's career. The Super Bowl team was built on a 7th round pick. Meachum was a bust. And Henderson never lived up to being a 2nd round pick although he did become a good deep threat after a few years.
So it's not really fair to say that we were good because we spent high round picks on WRs and RBs. We were good despite bad picks at WR. Mostly because Drew Brees could throw anyone open.