Hey, here's a really interesting piece of history. Its the Fighting Fantasy Mass battle rules put out by Warlock Magazine back in the distant age know as the 1980s. It was scribed by a chap known as Graeme Davis to boot. In fact, it was only because Graeme mentioned this pdf on Facebook that I was even aware of its existence.
I won't trouble you with a long investigation into the piece, but its well worth reading for a different take on a set of fantasy battle rules, especially considering its relationship with the rest of the Fighting Fantasy range. With miniature releases on the cards and Oldhammer Community members toying with fighting the Trolltooth Wars in miniature, this set of rules may well prove useful to some.