But, I have a bit of trouble with the interactions of this rule: if the pikes advance as a group (say two wide and two deep) then (I think) that isn’t a column, since columns can only be one element wide. If one of the front pike elements pursues, does it then become classed as a column?
Yes, you’re right. Ccolumns are only one element wide, but can be as deep as you want. (Although watch it; two elements columns can recoil; a three or more element deep column that sees the lead stand lose a combat and need to recoil, will lose that stand as it cannot push back more than element and so will shuffle off this mortal coil. Or become an ex-element).
So, yes, during combat of the aforementioned group of pikes in a two by two formation, you immediately apply the results of the combat dice roll. The one pike stand, if it wins, will advance, together with an element behind it. (Note that it can be any element, not just an element that can support the front element). Then the other stand will fight, but obviously its enemy will then receive a -1 modifier, as it is now overlapped by the victorious stand that just advanced.
As for DBA style Pike & Shotte rules, there were at least two Wargames Illustrated articles that had authors trying to adapt DBA to the Renaissance, long before DBR appeared. They both had a “Pike and Shot” troop type, as an integral single stand. Not sure which issues, but definitely before DBR appeared.
I remember when DBR was published, and Phil went to various conventions introducing players to his new rules, I asked Mr Barker if he had seen those rules in WI, and whether he had been influenced by any of their ideas when he was developed DBR. He categorically told me “No”. I think I inadvertently insulted him! I certainly didn’t mean to! Then I compounded my insulting behaviour by confusing his demonstration armies’ artillery and dragoons with each other. In my defense, they were 2mm – so the artillery had slightly larger bumps at the front (the guns), and smaller ones at the rear (caissons) and dragoons had smaller bumps at the front (the dismounted troopers) and larger bumps at the rear (the horses).
I don’t think he was terribly impressed with me!