Imagine Civ5 had been released with panzers and warriors switched around, all ship graphics substituted by horsemen galloping over the sea, while the ship graphics are used for mountaineering units on land. Theatres are now called supermarkets, Forges are called jabberwockys and require the bubblegum resource (which replaces iron) as well as the finger knitting tech, and Napoleon looks like Groucho Marx in a catsuit.
Would you really enjoy that game exactly like you enjoy Civ5? Remember, the gameplay stays _exactly_ the same. All I did was changing labels to reduce the "realism" part that you deem insignificant, so there shouldn't be a difference.
I don't think this is really a reasonable scenario, since you haven't described any kind of tradeoff. I think it's implied that when you say one thing is more important than another you'd be willing to give up some of that latter thing to gain some of the first. Let's say you did everything you describe, but in addition the AI now knows how to use ranged units as dynamically as a human player. Which game would you enjoy more (that may be an extreme example, one could pick something else instead, but something that would meaningfully improve gameplay)?