The Forces list there is a bit ... too encompassing. With that list, it might sound like half the British military is deployed just to Afghanistan
actually deployed "heavily-armed" units as of that list (by going through the units' pages):
RM Armoured Support Group - one BVS10/Viking squadron
Light Dragoons - one CVR(T) squadron
Second Royal Tank Regiment - one Scimitar squadron
19th Royal Artillery - one battery 105mm guns
39th Royal Artillery - one troop MLRS deployed (4 vehicles)
everything else deployed is: infantry, HQ, signals, logistics, medics, artillery fire control, helicopters (CH-47) and aircraft (Harrier, C130) with their maintenance forces.
Not too sure on future Warrior deployment. The various Guards' regiments mostly have their Warrior bataillons in TELIC right now - i doubt they'd directly transfer them from an Iraq tour to an Afghanistan tour.
Btw: Aren't there supposed to be British Apaches in Afghanistan? Can't find units for that in that list, unless they've been attached to other squadrons.