They seem to have a formatting standard at GMT, but no more than that.
I don't think they could do the kind of boilerplate that worked for SPI - the games
are just too different. On the other hand, the stricter formatting rules worked on some pretty
different SPI games (think Freedom in the Galaxy, Canadian Civil War, John Carter,
Empires of the Middle Ages), so I dunno.
I think the old SPI or Avalon Hill rules were all standardized by in-house editors. GMT doesn't have any editors imposing a uniform style - their formatting is basically just visual, probably whatever Rodger MacGowan formats them into. Since all their games are designed by independent contractors, you get the sort of variance in rules writing that you'd expect from independent contractors all doing their own thing.