Am I making Tanks too complicated?

Hey, all,

Here is the situation...with builds as I have them...

Tank 1 (Stacks at 1200-1250)
Diaz-III
Super Transmission Engine-III x6
Gravity Maint. Facility-III x1
Particle Stun Shield-III x4
Heat Diffusion Shield-III x4
Missile Interception-III x3
Orbital Shield x4

Tank 2 (Stacks at 1000)
The Shuttler-III
Super Transmission Engine-III x5
Gravity Maint. Facility-III x1
Energy Shield Booster-III x3
Particle Stun Shield-III x3
Heat Diffusion Shield-III x3
Missile Interception-III x3
Orbital Shield x15

Tanks 3 (Stacks at 900)
RV766 The Explorer-III
Super Transmission Engine-III x5
Gravity Maint. Facility-III x1
Energy Shield Booster-III x3
Particle Stun Shield-III x1
Heat Diffusion Shield-III x3
Space-Time Magnetic Shield-III x1
Missile Interception-III x2
Fighter Interception Cabin-III x2
Agility Booster-III x1
Orbital Shield x13

Here is the quandry...

If the Diaz tanks get hit, they almost never take damage...from any type of weapon. However, when the other tanks are hit, they often take damage...sometimes quite a lot of damage.

Am I overthinking Tanks? Would simple be better on all my tanks just to have straight damage reduction and more shielding? Why is this happening?

By the way, the Commander with the Diaz tanks is Angla...so she does not play into the discussion. Also, I'm referring to Instances. I do not do enough PvP to compare.

Thoughts?

Jycard

Here's how it looks to me Jycard:
You're shooting yourself in the feet with the numbers.
First off, your Diaz ships have a total of 8 absorption modules, and you have them in stacks of 1200. Then you have fewer absorption modules on your Shuttlers (only 6, but the 3 ESB modules help), in stacks off 1000. And finally your RV ships have only 5 absorption modules, and are in stacks of 900.
Diaz: High absorption + Large stack = great tank
Shuttler: Medium high absorption + medium high stack = good tank
RV: Medium absorption + medium stack = decent tank

My shield calculator could help you out a bit I think.
Diaz(1200 stack): 340k, 388k, 316k, 316k absorption against kinetic, heat, magnetic, and explosive respectively
Shuttler(1000 stack): 267k, 297k, 252k, 252k absorption
RV(900 stack): 189k, 225k, 193k, 184k absorption

So my answer...is that my Shuttler and RV tanks are too complicated? I agree that the stacks are doing some of this, but does that mean all my tanks would be better with the basic, low-level absorption shields over the specialized ones?

Thanks,
Jycard