Lexicus
Deity
That's fair, but in terms of where the franchise is at / where it's going, it's dramatically out of date. The 1UPT vs. MUPT discussion has been done to death in every Civ game subforum on this site since V was released, and it's not even accurate unless you stop counting at CiV!
All indications I've ever seen are that the dynamics of combat in civ 6 are highly similar to 5, with carpets of units that devolve into a sliding puzzle and the AI not being good enough at it to offer a real military challenge to a competent human.
In the original Civ, when a single loss wiped the stack? Yes, positioning was important (unfairly so, I'd say - I'm not saying this was a fair mechanic, it's just how the game worked in its earliest iteration).
Positioning is also rather important in civ 3 and 4. Being on the forested hill as opposed to the grassland tile really matters if you're fighting on close to equal terms (if you have enough of a tech lead, very little else matters, but this is certainly also true in the restricted-stacking civ games).