Gny, I don't think anyone sticks to linear deployments per se, but you're question is one best answered on the Arty Ops course.
I would argue though we do need Regt's, and not just to Force Generate. I'll take a stab at an explanation though...
Artillery must retain its flexibility to mass or become decentralised as needed, and we should not be steered by current ops to reorganize ourselves to the lowest common denominator, Bty deployments, but we do need to consider the realities of what we actually got.
As you should know Artillery is grouped as needed, reinforced where required, commanded at the highest level but responds to controls at the lowest level. All that to say it gets focused by the highest level commander, based on the senior gunner's advice, on where those Artillery assets can be most effectively used to influence the battle space.
Doctrine-wise a Regt supports a Bde, but there are a lot of possible situations that might occur, and each might need a different type of massing of forces to respond to. For example that Bde might have 3 separate BG's maneuvering, with each possibly supported by a Bty, or one of the BG gets 2 Btys support and one BG gets 1 Bty and the 3rd BG gets none, or one BG gets the whole CS Regt plus a reinforcing or even possibly a Gen Support Regt reinforcing as well, or none. The Arty Ops course should be teaching how to achieve that kind of flexibility, especially on how to mass should the Bty's be deployed with some distance between them, as I think you're implying. You need the Regt level C2 to achieve that kind of flexibility.
Whole fleet management and Force generating reality however dictates that we must be prepared to support a tasked BG with a Bty on 1st line of ops, and some FOO/FAC and SCC's on a 2nd line. The wild card is the remote possibility of a surge or spike deployment of a Regt, in either a Close Support or CS/reinforcing role (assuming neither 1st or 2nd line of Ops forces are committed). Remoter still is the possibility of a General Support Regt deployment (which doesn't actually exist right now in our ORBAT, but usually has rocket and STA capabilities with accompanying SCC's and maybe even AD) .
I don't think we need to change too much to our doctrine, and it might be a moot point anyway. In the short term, I think we will see even the Bty deployments come to an end post 2011 and actually see only the support to 2nd line of Ops type of commitment happening, if anything. That by itself does not mean we should give up and loose the Regt level capabilities.