It's fluffy I know, but I'd kind of like to take a blackpowder-less list. How would you go about doing something so heretical?
The problems are:
-Big scary characters
-Mournfangs
-Monsters
-Flying characters
I think that with proper construction, you don't really NEED a cannon. And the 300-420 points that it saves (2 cannons, master engi and a HBVG) can be spent on multi-purpose units. In my list, I'd use the 425 for 5 DGK's (upping the unit of 4 to 5 for a total of 10) and buy a war altar.
To get the multi-wound capability, you can grab beasts on the weaver. Not the best, granted, and not necessarily better than light/war altar or heavens, but it gives you that d6 s10 that the cannons lose. Maybe get a luminark?
Fun thoughts. The Ulric-ian fluff bunny inside is very happy.