Since we're going outside Freespace for ships...
This is relevant!To me, if Starfleet was going to design a ship to fight the Borg, it would have come out a lot more like the Sovereign than the Defiant. For starters, the Sovereign looks more like an evolution of Starfleet technology, while the Defiant looks like it started completely from scratch. Beyond that, though, the Sovereign class could clearly push deep into unknown territory, looking for Borg targets to attack, fulfilling both the need to deal with the Borg and Starfleet's exploration mandate. The Defiant class, while combat capable, pretty clearly isn't meant to be away from support facilities for extended periods.
It might help if you remembered the conditions the Defiant was designed under. Wolf 359 had just occurred. The traditional cruiser-style Starfleet ship had failed completely and the Borg had smashed forty of them. It was a time for new solutions, and to consider defense over attack.
The Defiant is small, fast, overarmed, undercrewed, and cheap. They were designed to fight the Borg and to minimize the loss when they died, because at the time they were designed it was assumed that the vast majority of ships which engaged the Borg would become causalities. It had the weapons to do significant damage while it yet lived. Defiants are meant to come at their opponent in swarms, in much the way Starfleet has always ended up having to fight the Borg, and to live just long enough to complete one or two runs with their insanely overgunned battery.
By any standards they more than exceeded these design requirements, particularly in terms of survivability.
Belkan Ship of The Line, Lyrical Nanoha. (No, not the Saint's Cradle in particular, just the line of ships it descends from.)
