The point of departure between the TT's approach and mine is simply this -
The TT's premise is that any Navon [must have] had all the rest of the middot, too.
I'm questioning that way of thinking and saying "lav davka"
One can be a navon and still be lacking other traits
EG In baseball.
Just because a guy hits for average does not prove he hits for power; or vice versa!
Just because X is a lamdan does not mean he's upright
And Vice Versa
Just because Y is upright does not mean he's a lamdan
Therefore the failure to appoint N'vonim does not PROVE that none existed, rather it may be that they DID exist but none of them otherwise qualified.