That’s great and strangely accurate. I suppose it takes one really successful game spawning a load of copies to create a genre and it didn’t happen until Dune 2 came along.
One of the first games I ever played on PC was The Ancient Art Of War which I’d consider an RTS and that came out in 1985. You couldn’t build anything in that one though so were stuck with your starting units. It would be a fun series to cover one month (not that there is any shortage)