I think this is a very helpful overview of Ogre Mercenaries. I almost always add at least a unit of 3 bulls. I have found 4 leadbelchers to be 1 too many, so it was good to see you recommend only 3. I'm still converting up a maneater and some Ironguts.
However I am surprised to see no mention of Rhinox. I have a single Bull Rhinox pimped out a bit with armour. Its really quite a handful at a fairly reasonable cost. I would call this the ultimate Deathstar unit. Plus converting one was one of most fave projects ever.