I played chess since I was 8 years old for 40 years. I played weekly in clubs and tournaments for about 25 years. I have good spacial imaging. I can remember whole games, exact positions and can play blindfolded. I have good hand/eye coordination which doesn't help much in chess, but is important in realtime computer games. After I stopped playing chess regularly I played online computer games like C&C, Warcraft, Doom, Quake and Counterstrike, and tried very hard to be good at those games, but I wasn't. Then STW became available, and I was good at it in online play from the very beginning.

I attribute this to my experience playing chess because I had learned to coordinate 16 pieces, could visualize the entire battlefield and I knew the importance of making a strategic plan in a tactical game. In STW, you have to use each unit individually but also coordinate all 16 of those units. You can't use the units one by one which doesn't work in chess either. It's bad to overlap units in STW, and in chess you can't overlap pieces. Fast reflexes wasn't the overriding factor in winning in STW, but you did have to assess and react to situations in a timely manner. You can play team games in STW which expands the strategic aspect to a level above chess.

In STW you have to protect your general, and in chess you have to protect your king. As you play, the number of units or pieces left diminishes with no way to replace those losses. The total number of units in STW is the same as the total number of pieces in chess, and the unit choice is limited to 4 functionally different types. STW has ranged, cav, spear and sword. Chess has the 4 different movement types of rook, knight, bishop and queen. So, the complexity of the task of coordination is similar. Both players choose from the same set of units as in chess. As a result, positional play is paramount because you can't get an advantage during the army purchase phase. It's the same in chess in that you gain an advantage by where you position your pieces. Since you can't simply rush the other player off the board in either STW or chess, you have to try to accumulate advantages in the conceptual areas of time, space, and force. You have to be constantly weighing the offensive and defensive capacity of the position until you have achieved a winning advantage.

So, I believe their is a lot of similarity in the thinking process used to play chess and to play STW. This similarity has steadily declined in each iteration of Total War beginning with the Mongol Invasion add-on and continuing through MTW/VI and RTW/BI. For RTW, I would say experience playing whack-a-mole is more useful than experience playing chess.