For saxes at least, it’s more than just the legato. The whole approach is really from a classical sound perspective. If I take an example like this from Cannonball Adderley …
… I would notate it like this:
Mark the longs and shorts on quarters, but other than that the player really already knows what to do, and anything else is unnecessary clutter. NP of course plays that like this:
Switching to Legato is certainly an improvement, but still not great:
Even if I write in all the phrasing like this …
… NP still has a very classical approach to it, even on the slurs:
Something like VHorns does a lot better with that marked up file: