Bend but don’t break is not a philosophy, it’s a result.
Defenses that are aggressive give up big plays. The break rather than bend.
Meaning they will go all out to stifle every play at the expense of giving up big ones when they don’t. Defenses that prioritize limiting big plays bend, meaning they will sacrifice all out on a play in order to not allow the big play.
Both defenses intend to stop the other offense. A good aggressive defense gets away with their aggression and allows more, but not too many big plays.
A good conservative defense allows more but not too many first downs.
Bend but don’t break refers to a defense that isn’t great at executing in - territory and into +territory but us very good on their side of the field. That defense neither doesn’t care about stopping teams in their - territory, not becomes better on their side of the field because if it.
It’s not a plan, it’s a result.