I'm not sure what you're thinking or trying to get across here, but you're not telling me anything I don't already know.
What you're saying is what has already been known; that every rank earned in Percpetion/PF/Dodge/CM are all weighted equally in the equation - yes, we know this.
100 ranks of perception is the same as 100 ranks of CM or Dodge or PF.
200 ranks of perception is the same as 200 ranks of CM or Dodge or PF.
What I'm saying is that there is a diminishing return to your actual SMR defense you see in the visible roll that shows up on the screen based on information I've seen from testing things out.
Think of it this way.
Every spell rank up to your level gives you +1 to your casting power.
Once your spell ranks exceed your level, you only earn +.5 for every spell rank known.
If you're level 100 and you have 120 spell ranks, you're casting power would be increased by 110 (100 for the spell ranks up to your level + (20/2) for the 20 spell ranks past your level. So you end up with an increase in power of 100 + 10 = 110)
The same thing appears to apply to SMR defense. There is a diminishing return in the actual SMR defense you see come up on the visible roll.
That's why I say it's not really going to benefit you much to sink 50 ranks into dodge as a pure, simply due to the low SMR defense you'd get in return. I'd only suggest dumping TPs into dodge if it was the last thing on your list of skills to train in.