I tend to agree with @'tarako. Pressure > Endurance. You are immune to (better than saving!) every spell they can't cast because they are fleeing or otherwise on the defense because you are hitting them like a truck.
Pressure doesn't have to be simple damage output...it could be disruption skills, but usually, it is damage. Cue whip lore's immense power in applying both damage and disruption plus the ideal weapon type. Similar situation with exotic lore.
Control the initiative like that and you'll control the battle.
If you can't output enough damage (e.g. against clerics), you'll eventually (or quickly!) lose if the player is good enough. That is the essence of why clerics are so dang strong and effective in PK. It is also the reason that non-giant-sized heavy melees are relatively bad: they trade offense for 'protection' and end up having neither as a result. A strong offense is an exceptional, and cheap, defense.
Of course, it works in reverse too. A dispel causes immense pressure/disruption on the melee and gives the caster the initiative. Who needs blind fighting when they are pin-balling from your flame arrow chasing and trying to put spells back up? Cue herb complaints.
It is easier for a caster to reset encounters/break your saves than it is for you to 'outlast' them with those saves. If they can't break your saves? Reset and try again. If you can't deal enough damage? You will lose. Thus the original emphasize on damage over protection.
Best case, naturally, is to have both. Traditionally easier for casters since their damage requires less eq slots to 'empower', but from the forum, seems to have been very easy for melees to have both in more recent history before the EQ revamp.