Show a couple episodes where Voyager has to run away.
(Janeway said in an episode that she was sick of running away and hiding, but we never saw it.)
Or an episode where they're on silent running hiding in an ocean as a Borg convoy passes by very slowly.
Sheridan spent years running from the Shadows.
O'Niel couldn't do Jack (Look! It's a Pun!) against the Goul'd or the Ori in the beginning.
Obviously not invincible, the Borg are still a vastly superior technological species with the fire power and man power to dwarf anything Kathryn can muster but she treated them like bullies on a school yard, rather than bullies invading Poland.