you realise that cain has mechadendrites right?
theoretically he can propell himself forward with two of them to close with the enemy in the time it takes to draw his new chainsword, and with the other two clothesline at least one or two on each side, provided they dont duck, or his can impale one with each mechadendrite, this is not including the drawing of the hellpistol and chainsword, which could account for a further two or three, just as the gangers open fire.
join that with the skill and combat abilities of the other acolytes, and i think you underestimated our strength tain.
we could, with a small amount of luck on our side, decimate such a poorly armed group of that number.