That's why you can AUTO battle in TW. Fight the interresting battles, leave the rest for calculation. That solves the "time-consuming" and more so; it prevents repetative actions (see below for example, but i guess you can come up with much more repetative actions with a very much predicted outcome).
Honestly, why is that bad and seeing your spearman winning every battle in CIV5 against the barbs over and over again would be any better ?
The only solution for tactical warfare is realtime, 1upt HEXs/turn based just does not cut it. Period!
In that sence, all debate about "tactical & strategical" warfare in CIV is "nuts".
Auto battle is bad. I've used it in several games to always have, at one point, the ai lose a whole army where, if I took control, I'd win without a single loss. But I'd have to use boring tactics. Those battles lost in auto-battle weren't even challenging or interesting, so it was a chore to play them out. So your argument about auto battle is worth nothing ass far as I'm concerned, it solves zero issue.
As for seeing the spearman win every battle, I turn off the animations and it gets faster.
Realtime is not real-time, it's click-fest time. A real time battle would take hours to play out.