Did you watch "Emissary" - the Melbourne lasted about five seconds. The Saratoga lasted at least a few minutes.
Getting lucky against the borg (before the Voy happened) isn't much of a fair guess. The GCS was the ship to beat the borg when a whole fleet couldn't.
You mean the heavily refitted combat-orientated Excelsior that got beaten by a ship a fraction of it's size?
A heavily REFITTED combat-orientated ship that was a hundred years old vs the best warship in the AQ. Again it just seems so (NOT) fair. I love that in the end it was a DRAW. Neither ship was willing to finish off the other. The fact that such an old ship can be so well refitted for duty in war 100 years after she was built is a testament, not a fault.
Plus I don't remember seeing a Defiant Class in TOS. So those other ships are just S.O.L.