Thanks for the answer! In RTW I used to play VH on campaign difficulty and would vary between VH or H on battle difficulty. However I am still not sure how does the diffilculty reflect in game exactly. Nevertheless, I'll have to restart the campaign in a harder mode.
Refering to the bugs, it's hard to specify the circumstances...
- On the army draging bug, I simply chose 2 different calvary units, a general and a random cavalry, and draged them on the map as to position them in a specific direction, right? I usually hit CTRL + 1 before doing so to position them in a line close to each other, however this once I had forgotten to chose this particular setting. I can't confirm this was the triggering tho.
- The other bug is impossible for me to put in a set of circumstances. I remember this happening maybe 3/4 times during this campaign, it's not something happening in every single ocasion but seems kinda random to me. I would simply click on the button to start the battle and the game would crash. I then would have to close sesion in my laptop to be able to finish the process in order to close the game since it wouldn't allow me to change to another window once it had frozen. I will try to focus more on the circumstances surrounding these ocasions, but for now I am not able to think of more information, sorry