Maybe have Arthas set up the Cauldrons along the fields of the Plaguelands as he kills the Paladins on the second mission.
Before leaving for Quel'Thalas, we could see a little cutscene where Arthas leaves a portion of his army in some other Death Knights' hands. Maybe the Four Horsemen. To...
I'd simply have the campaign visit the Tomb of Sargeras island and some smaller islands around it. Have all the other parts of the Broken Isles simply be further away. Maybe visible in the distance, but not the focus of the events.
WoW maps are not up to scale, things are way bigger. Goldshire...
Maybe a little cutscene when Arthas returns from Frostmourne cavern, where Baelgun and the other dwarves leave the human camp. No more dwarven units for the finale.
I always found happenings there a bit strange. For example, Arthas says nothing about killing Muradin and the body is never found...
The problem with kodos is that they are not found in anywhere outside Kalimdor. So even Pre-WC3 maps can't really use them. The green ones could be added to bears (as I've tried once), but there really is no Outlandish creature for the fel ones. Unless someone could create Clefthooves from scratch.
Great models. Even know this is based on the movie, I'd still love to see a green (or darkish green) skin as well.
You might want to check that shoulder pad. It floats away from the back/shoulder, and it may need a bit of downscaling.
Also, any reason why he is left-handed? :P
Good job on creating female orcs.
I have a small suggestion: If possible move the angle in which she holds the axe. Something like on this picture. Makes it more natural to the way she holds her arm.
Ever thought of putting the Lordaeron crown (the one on the ArthasCrownPrince model) onto this unit or the mounted version? I always found it strange how the paladin on the second Undead mission says "You wear your father's crown as if you've earned it." yet Arthas was never wearing that crown.