Elite: Dangerous PvE - Mobius

I want to make sure I'm understanding how shield generators and hull mass interact. I have a ship I'm building, and it's hull mass is as follows:

Hull: 280 tons
Unladen: 450 tons
Laden: 546 tons

I want to use my largest module slot for a cargo rack, and still have decent shields for some light combat, so I'm installing a shield generator in the second largest slot. The optimal mass for the shield I'm using is 405 tons. If I'm understanding this correctly, this is more than sufficient as optimal mass refers to the weight of the basic Hull value, in other words the 280 tons of my ship. Is this correct or am I misunderstanding something?

Also, does this change depending on if you have Reinforced Alloy, Military Grade Composite, or Hull Reinforcements installed?

No your right.
Only thing considered for shields is the base hull weight.

Not modules or any other added weight.
Here's something to play with
https://coriolis.edcd.io

The Python is a good ship for outfitting for different tasks, light shields to escape rest all cargo or one 6A Shields, rest cargo if your going to turn around and fight. Or Tank her out including Hull tanking (Military) for Combat I have her setup to do that. Same for the Clipper and Conda both have a Class 7 Slot to play with, recently sold Annie too nosy, still have some of her Engineered Mods. There is the wait time transferring Mods not a big problem if you homestead.

Yeah, Python is my next ship goal after I fit out this AspX. Not really interested in Clippers or Cutters though, they remind me to much of the pinnaces from the Honorverse novels. I'd be too tempted to name one the Scotty Tremaine.

Oh yes, I've also known about Coriolis for awhile. It's where I got my numbers.