Ground guide for the Artillery is important, you have Gunners holding the trails up and they are out of sight of the driver. Note your driver drives, the ground guide guides. Guide signals stop you stop, they say left / right you turn the proper way. No hessitation. I always told my drivers your the one driving if you feel uncomfortable then stop and ask questions. If you feel uncomfortable backing up then lets practice, if you cant understand what it is I want you to do stop I will yell at you, say a few profanities and explain what it is I want you to do, then we will carry on. Last if it was just them backing up in a parking spot I would stand behind them in view of their mirrors and let them know if they were going to hit something. If they felt uncomfortable doing that then be prepared for the slagging to follow from a few of the others.
One thing that is important is prior to a road move you and your crew talk about what it is each is responsible for, you talk about how to turn back on the road, you talk about broken vehicle, you talk about speed and so on.
I always found on our road moves the Truckers would complain about the F*&(^%$ Army trucks and how they were moving so slow. One day I had a handheld talk about and asked them how it was we were passing them going up hill on the Snoqualmie pass if we were so slow. No replies and also no further grumblings. Once at the top of the hill they passed us going down the other side and flashed their lights.
No amount of ground guiding will make up for bad driving.
Every person who drives thee trucks should get a full day a month min to practice drving them, this includes off road usage (skill levels of the ability of the trucks what they can and cant do). Practice convoy driving, actions on in a convoy, city driving, backing up on their own and with ground guides, and self recovery and recovery of another vehicle. All this coupled into a training plan with a few other things and drivers would be excellant at what they do.
I agree we should use Convoy signs when travelling as such, We should also have designate lead and follow vehicles. These are able to travel to the front or back of the convoy with ease. A possible police/MP escort if travelling in more then a 4 vehicle formation.