Actually isn't standard armor 30/35/40 HP at TL 1/2/3 while emissive is 30/40/50 at TL 4/5/6? So at tech level 4 your emissive armor would be likely to get hit first, at level 5 your armors would have an equal chance to get hit, and at level 6 your standard armor would be likely to get hit first.
I like to think of emissive armor as a thin coating around the ship, so it's still on the outside in "real-life" terms, and it only works the way it does due in the game due to SE4's quirky rules about which components get hit first
If you want to model it this way in the game, make EA 5kT with 15/20/25 hitpoints, that way it tends to get hit first and you'll need a lot to make sure you can keep up the emissive effect as your armor wears down... so you'll probably want to reduce its cost as well
What's really weird is how scattering and stealth armor work together... one reflects and the other absorbs, so shouldn't they cancel out?
(Unless they reflect and absorb different frequencies of light...)