Gygax was involved in hex grid wargames and miniatures wargames before he came up with D&D.
I’m an old AH and SPI wargamer myself. Still have a closet shelf full of that stuff for some reason - Panzerblitz, Napoleon at Waterloo, etc.
Yeah, I have all the oldies stacked up as well. My first was the second edition of Gettysburg, when AH first introduced the hex grid. I played through the SPI and GDW monster game era. Haven’t played in years but I’ve not been able to resist picking up occasional Civil War or Napoleonic tactical games when I see them, on the theory that I might retire someday and need something for a rainy day. The old Marshall Enterprises games were worth getting just for the art — the prettiest counters ever devised by the hand of mortal man ....