^Wasn't Galactica's FLT also damaged during the battle of New Caprica before Pegasus came?
Getting their superior military ship destroyed while badly damaging their only remaining military ship (to the point where I believe Tigh or Helo said it would take weeks in dry dock to fix the scarring to the hull) was a pretty bad tactic, but I guess it got the job done. It's a good thing they have an allied basestar now.
Even undercrewed and with a badly damaged Galactica I would think they would be able to hold off 4 (3 really after the Pegasus destroys one in its surprise attack) Basestars, especially with Pegasus' fighter support. After all, Pegasus was able to survive a surprise nuclear attack by 3 basestars in season 2.