Having a flick round the OOB, I thought about the formations there. and it seems to me that some of them are missing or slightly wrong.
I've included some of the stuff which I'm basing my Ideas on, so you can have a judge.
The attachment is a Document from the army explaining the infantry organization.
Each battalion is either Infantry, mechanized infantry (Saxon) or Armoured Infantry (Warrior).
Each of those has three Rifle Companies and one maneuver support company. The maneuver support Coy has ATGM's, Mortar, ISTAR* and a Pioneer platoon.
In Leg Units the Heavy weapons are mounted in trucks. In Armoured infantry and mechanized infantry they're mounted in FV432's.
Also the commandos's have been regoranised to something called Commando 21.
An explanation is on the following link.
http://www.onceamarinealwaysamarine.co.uk/cdo21.htm
If you want some help with creating those formations, I can help.
*ISTAR:
Intelligence, Surveillance, Target Acquisition and Reconnaissance
Basically Scout units and Sniper's mounted in Land rover's's.