Extra secondary paths and fatigue reduction

[Yonz]

Playing Marverni I have found out that apparently having extra levels in a magic path does NOT reduce fatigue. I proudly kitted out a battery of druids (skull caps and all) to rain down stellar havoc on my enemies only to find them at 125 fatigue after only two blasts. What. The. Hell.
I'll take one of them for example, a 3E 4S 8 reinvig, 3 spell enc Druid starts at 25 fatigue, casts GoH and is now at 75 fatigue. No reduction whatsoever, despite his having 3 (!) points of extra astral.
Now, while I suspect I haven't exactly discovered America, I don't have the manual nearby. So, I can't really check if that is supposed to happen or there's something else afoot. Either way, I feel ripped off.