On board artillery spacing

[Grumbler]

I'm not fighting a 'real war', I'm playing SP. So if I'm using motorized vehicles, I keep the formation within C&C range. If I'm using fixed arty guns, I put them in rough hexes and hope my opponent shoots at them. A dug in turbe is very hard to kill, and for game purposes, a unit that starts and ends it's turn in the same rough hex gets the same defensive bonus as one that is entrenched. The only difference to me is that with fixed guns I buy ammo trucks and send them position to position to reload, while with mobile guns I buy fixed ammo supply and send the guns to them to reload. What I buy depends on the terrain. If I have lots of rough to hide in, I'll get the fixed guns, if there isn't much rough, I'll buy the mobile guns.
As far as spacing, I always keep my formations together. By together I mean all the units within the 5 hex C&C range of the zero unit.