Gems, fatigue and increasing magic levels

[RamsHead]

I just ran a test. I had a level three mage with a small army attack an independent group. The battle took place with a magic scale of 3, that's 30% reduction of fatigue. I had the mage cast legion of steel and invulnerability, which put him up to around 40 fatigue. Then I had him cast curse of stones, a level 3 spell with 300 fatigue and requires 3 gems, which the mage had. He cast the spell and had 200 fatigue. 30% off of 300 is 210. The fact that he cast it despite that he should have gone over 200 seems to prove that a mage could cast a very fatiguing spell at 99 and only be at 200 after it is cast. Of course, other tests by people to support this finding would be appreciated.