Back in AoW3, there was a very explicit visual distinction between units that had acted and units that have not. I'd expect that to be clear with the unit banners being bright or slightly greyed out, but instead that's an indicator of something else I've yet to figure out.
Especially in bigger battles, this makes it very hard to read which unit has moved and which has not.
And yes, there is a "unmoved unit" button. It is very unhelpful, because it goes by some arbitrary order, instead of located somewhere near my area of interest.