Her "arrogant" pushiness was apparently a driving force behind the anti-Borg operation that impressed a Starfleet admiral. And while there is no direct evidence of this, it is a pretty safe conclusion that this same program, under Shelby's administration, ultimately resulted in highly successful anti-Borg defenses such as Sisko's Defiant.
We will have to agree to disagree on much of it, but I wonder about her success with anti-Borg defenses? The fleet in First Contact
was getting its ass handed to it until Picard came along and showed them the magical spot to hit. The fleet at Wolf 359 also got their collective asses handed to them.
Starfleet got lucky twice beating the Borg in the Sol system, I'm not sure I give any of that credit to Shelby.