Or am I doing something wrong?

I get assigning scripts and turning party AI on (so they don't just pick their noses while I get slaughtered) but is this something I'm just going to have to adjust to, or perhaps an unfortunate side effect of a mod I have installed? :p

Any help would be appreciated :)

No, if you have assigned them scripts & have AI on, they should attack as per script.
Toggling AI off & then on again doesn't help?

They attack fine if they're in range...I mean follow my main character around as she moves across the map (not in combat, in other words). If I don't highlight and click on the map for them to move (or use the group select feature) then they just stand off in the distance.

Appreciate the response though!

That is what group select is for.

OK, just checking. I didn't want to have to keep doing that if there was an easier way. Thank you. :)

...how do I mark this as "solved"?

You can only mark it as solved if you post it as a question by putting a tick in the box when you start the thread.

This is very much a game that needs micro managed. (DragonAge 2 "players" need not apply) But once your hooked, you'll be playing it for years.