Possible scenario for Afghanistan.

[IronDuke99]

If you watch the documentary, and freeze it when the plans of the position are shown, you can see that the 'compound' the British were holding was both fairly large for a company sized force to defend and also surrounded by buildings at a very close range, one or two of which even overlooked the British position.

So the enemy has plenty of cover available and they should also receive regular reinforcements, including at least one large scale reinforcement. The British should only have a very limited amount of air support available.

The Brits on the other hand had better prepared cover, body armour and better night vision, etc.