I don't think that the LtAD units (Bofors ,Thunderbird and Rapier) were Division assets. Certainly in the 1960s, when 22 LtAD moved from Pembroke Dock to BAOR, they were grouped together (12, 16 and 22 plus the two Thunderbird units) into 7th Artillery Brigade. This , of course, could have been changed, as the only Artillery Brigade I can find is the 1st (HQ Hildesheim), which had the Heavy and Missile stuff.
I would assume that they became divisional assets when they changed from Rapier to Stormer/ HVM.
Incidentally, the cyclic rate of fire for the L70 Bofors was 240 rpm, although only 160-180 rpm was practicable, and then the barrel started to get a little warm! The only aircraft shot down by a British Bofors in "peacetime" was an Indonesian Hercules over Borneo (40 Bty "The Old Rooks" from 22 LtAD Regt, I believe).