One more interesting bit about this song and it being in open G. Open G was a Keef thang and a great number of Stones songs are in that tuning. It's common knowledge that Ace was/is a huge fan of The Stones and Keith Richards. They covered 2000 man on one of the last Kiss albums Ace played on. Dynasty I think ( my first rock concert by the way, October 2, 1979 at the old Checkerdome, touring on that album. John Cougar opened and was booed continually until he left the stage). Roger Waters learned the open G tuning from Keef, hence it's use on Fearless ( Yes Roger wrote that even though it's Gilmour playing it on the record).
For me anyway, when I tune a guitar to open G and start noodling around, those two songs immediately strike my mind and it's impossible not to play them. Both are relatively simple riffs and took me less than a few seconds to pick out.