Most frigates will probably use the 0 cpu platings as they don’t have the extra CPU for energized, or cap for active hardeners. There are also some niche uses for the deadspace adaptive nano platings as they have similar stats to some of the lower tier enams, but use 0 cpu.
Heck on frigates a lot will rely on the hull tank and just use a damage control with some transverse bulkhead rigs then a small ancillary armor rep. with 3-4 lowslots on most frigs it can be hard to fit much of a tank.
On larger ships the Energized Adaptive Nano Membrane II (EANM) is the foundation of most tanks (and consider a faction/deadspace versions for more expensive ships) a Damage control + 2 EANMs is a pretty decent omni-tank for most ships. Can add reps or plates depending on what you are doing. Some will go full passive plating as it’s always on and in big fights there can be lag that makes active hardeners unreliable.
For some t2 versions of ships they will have a resist hole, so they will probably use a specific Energized Membrane (or an active hardener) to plug the hole. Like gallente + explosive, or amarr + thermal.
in pve when you know what you are fighting using active hardeners is very useful as they give large resist bonuses and on a pve ship the cap use is pretty reasonable. Although for missions I usually use an EANM based tank because I’m experienced enough I don’t need the extra tank plus I’m too lazy to swap.
Super capital ships often have a full set of x-type active hardeners and a-type passive hardeners. They will refit depending on the situation. the actives give far more tank, but as said earlier they are active and can be ineffective in large fights. Also they use cap and often supers get neuted out and with no cap no resists that makes active hardeners useless.
Don’t forget your Damage Control Unit either. The armour resist bonus is small but is not a victim of stacking penalty like the rest so it will do a lot, and the extra hull resist will allow for extra GTFO factor.
Also take into note, that the normal meta, is to use either high resistance modules and armor repairers, or high resistance modules with large buffer, i.e. HP.
yeah, but ive got a dual deadspace medium armor rep cap stable cloaky legion that i love to fly with. if you got the skillz and are a pretty cool dude, cap isnt a problem.
Resistances cut how much damage you take which makes things easier for the rep module, this is true in both pve & pvp
For pve I’ve mostly ran with 2+1 hardeners & 1 Rep module, that usually leaves me with some wiggle room for +dps or +tracking mods depending on the ship im flying.
The usual difference between incoming damage in pve & pvp (say 10k dps as an example)
pve - you’ll experience peak damage of 500 for 1 second, so you need to run your tank for 20 seconds to survive
pvp - you’ll experience peak damage of 2000 for 1 second, so you’ll need to survive for 5 seconds
resistance + reps is more suited to the low damage over a long time that is typical in pve
resistance + hp is normally better for the much shorter time frame pvp occurs over
that said, what type of pvp your doing will influence how you fit your ship
fleet or large gang fights you may be able to rely completely on logi’s so you wont need a local rep at all
small gang fights, you may need to be more self sufficient, there may be logi, but it’s more likely to be successfully primaried