So here's my crackpot theory right!

In my first playthrough I invested heavily in endurance to block, dodge, and use my heavy weapons, I had a lot of raw durability from my armour but next to no FP so I never used summons. In my second playthrough I've invested heavily into mind to the detriment of endurance, my weight capacity has gone down so I don't carry a backup shield anymore and my armour is much lower, but now that I have so much more FP I can summon far more liberally.

In both cases and both playstyles I have almost exactly the same amount of net survivability! I really think the game intends for you to reach this level of survivability naturally in whatever form it may take be it a pure mage build that uses a shield to absorb melee and their cloth armour to absorb magic, or an agile build that enjoys light rolling.

If you choose to have anything less it's entirely up to the your discretion and only represents an increase in difficulty not a division from the intended difficulty of the game.

Except Mimic Tear, Mimic Tear is a crutch.