And it remained Defiant to Starfleet's long-standing tradition of (supposedly) not being military

One of the traditions on the Defiant during the Dominion War was to literally stack up the burnt-out phaser emitters in the mess deck.

Yeah, this thing was TOTALLY a military warship, and, honestly, it heralded in a new era for Starfleet where they FINALLY admitted that, yes, they should probably have some segment of them that /is/ proper-military, and capable of holding off Big Bads like the Dominion.

Of course, then there's Section 31, which is a whole different ball of wax...

In any case, yeah, the Defiant is massively overpowered in every possible way that word means, to the point where it was an absolutely naked deus ex machina.

Still a hell of a ship.