Yep time to dive back into the Orks.
I see no reason to run the Decurion if you're not running Ghazzy and the council. Sure waggh! is nice every turn anyway but fearless is even better.
My first stab at it:
Core: Waaaggh! Band.
10 Boyz, nob w/pk&bp
HQ: Council of Waaaggh!
Warboss, pk, 'eavy armor
Warboss, Mega-armor, lucky stick
Nobs x3, 'eavy armor, Waaaggh! banner
Mekboyz' Big Stuff
Battlewagon, ram, big shoota
1850 exactly (ITC).
The tax on the core choice is just too high IMO. 6 units of boyz is stupid if you're not making a Green Tide (which, btw, is gone). Either that, or allow Ghazzy to be taken as a warboss in some other formation other then the council. Something.
The Decurion falls well short of competitive, but it sure is fun!