The best change is probably the one you are most loathe to do.
Looking at some of the Tolkien maps:
http://hugo1900.pagesperso-orange.fr/MA ... ION-7.htmlThe change I would make is to adjust the map itself slightly for game play.
1) Move Moria about 5 squares to the north
2) Move the Isengard area about 10 squares to the north. Move the river only 5 as part of Rohan movement and then just have the other 5 be the river curving to the north.
3) Move Rohan/Gondor/Mordor about 5 squares to the north (shrink the area above Mordor to that water by those 5 squares)
4) Move the Dwarf Iron Hills area about 3-4 squares to the left and potentially south a couple of squares.
5) If you are really ambitious I'd also move Gondor/Rohan/Isengard around 2-4 squares to the left as well to give a bit more separation to Mordor.
This will bring Isengard/Shire closer by 10 squares to conflict and make Isengard better able to aid the Witch King. It will also spread out the distance between Rohan/Isengard by 5 squares to prevent early crow/rush tactics. It also allows Rohan/Isengard/Gondor/Mordor a chance to get to Moria/Mirkwood before the game ends (those areas are almost never used). The Dwarves will enter battle slightly sooner and have a better chance to come into conflict with Mordor. Lastly it puts Haradrim 5 squares further from Gondor allowing more time for Gondor and potentially allowing you to give another city to Haradrim due to the fact they'd get into conflict another turn or so later.
KGB