If it's firepower the army are after, why don't they make better use of the stacks and stacks of air assets (including AH) armed with precision-guided weapons that orbit daily over Helmand? Given the small distances involved, there's always something within a few minutes' flying time, which means that the required 'smack' can be laid down in much less time than it takes to roll out a Chally - which at the end of the day is unguided artillery on tracks...
And TTH's point about the multitude of UOR armoured vehicles is well made; what a waste of time that all was, if the answer was sat in Germany all along.