Skull of pain rage regen question

[Fatt_Shade]

Lets try this from economy aspect :
In Ap/Cw all hero classes have rage skill in might tree(so pain skull is NOT only way to go for rage fans). In the Legend only warrior had it, and skull of pain was great item to keep for paladin/mage because there was no other way to boost rage inflow.
Pain skull +2attack , +50% rage inflow.
Skull death +5attack , +5intellect.

Lets for mage class add Heroism skill 2nd lvl and Pain skull = +6att , +50%rage inflow (for 12might , 3mind runes) OR Death skull and Rage skill 2nd lvl = +5att , +5int , +40%rage inflow (15might 4mind runes).

So you get -1att , and +5 int for 4 more runes (there is no skill in whole game that gives you +1stats for 1rune cost). And you destroyed it for 3 magic runes, that mage class have plenty of. Waste.

As for turning item in pure generic stats boost :
+5att = 16.5% higher dmg for your units vs enemy.Same as leading 16.5% larger army, in case you have some 10K lds equals to 1650lds.
+5int = 5x5%dmg , and if you make multiplier of 7 with this 5intellect bonus it`s +15% more so with this item it`s possible to get 40% dmg to spells, and if you pass multiply of 15 intellect, +1 duration.
So how is this item trolling from dev`s ?