My Idea to Improve attunement

This Idea adds an extra Attunement bonus to skills that are teir 2 and up because they have Prerequisite skills to learn before learning the skill. So if you cast a damage spell say Banish Undead; you would get the normal life attunement thats added in your damage, then a Prerequisite attunement bonus. Banish Prerequisite is PURIFY, so the lvl of PURIFY adds another number to add to attunement.

RULES

the Prerequisite skills must be part of the 10 skills that add to that trees ATT.

the extra bonus has alot of possible parameters:
Prerequisite skills must be higher then the skill ahead of it in tree to contribute to extra Prerequisite ATT bonus.
So if you have a lvl 100 banish undead your Prerequisite skill PURIFY must be 101 to contribute