Are the Minerva SA values based on the Lewis MG used very early on or the Hotchkiss 09?
From what I can determine, the majority if not all of the British armoured cars used in the late scenarios were early ad-hoc models, not the Rolls-Royce armoured car 1914 pattern, which only arrived in December or so. The unit name of the Eastchurch squadron also mentions the ad-hoc nature, but the picture displays a 1914 pattern Rolls-Royce armoured car.
They were cars fitted with armoured plating, but not "genuine" armoured cars like the 1914 pattern.
http://www.rrec.org.uk/Cars/Rolls-Royce_...Action.php
Also: if they used the Maxim, shouldn't their SA value be 40 instead of 28 or would that make them too good and was it a design decision to limit their SA value?