More alternatives in the development in the story.
In the existing games, you can choose only from time to time between 2 different troopmovements on the map.
Would be nice to have more of that kind of features.
Also it should to be beter intergrated into the development of the story and the introduction of unittype by levels.
The overall progress of the game doesnt always have to be related to the winning of a single battle/campagne. It will be more interesting to see how the story goes if you fail/win some of the campaigns, but with a similair ending.
An example: a single event (return of Kane) trigger multiple alternative timelines and then gradutely convert into a single event again . see diagram below. Interesting see how it works with different factions aswel.
I would love to see some turnbased features back in the new game, like in the wrath of Kane.
A more dynamic development of the story. Adding an extra layer to the story beside factions.
If the timelines are not carefully structured, some players can get really confused.