Sat Jul 07, 2012 8:32 pm
The trait states: "20% combat bonus for all artillery units in the stack this leader is in. Apply to all stacks in the region if this leader is the most high-ranking officer in the region."
The first sentence says there is no reason to do other than placing the Artilleryman in the stack, be it a loose stack of units, a division, and corp or an army. Since corps can command more units than army-stacks, you will get more Bang-For-Your-Buck™ by placing an Artilleryman in corp, if you are filling them to the max, which if you have a good corp commander in a good army, I would do.
The second sentence points to an advantage to all units in the region, if the leader is the highest ranking leader in the region. But to arrange for that without jumping though too many hoops or building a force disadvantaged in some other way -- most leaders with Artilleryman do not have that much seniority nor other good leadership traits (offesive/defensive ratings), and most leaders with lower seniority have poor leadership traits too.
If you have an Artilleryman such as J. Gibbon, who is also a good division and corp commander, I would not hesitate to also give him a division or corp. When giving him a corp you might want to tune the corp to have extra artillery to make use of his special ability, but that would depend on the situation.