I think KGB's suggestions are spot-on. However I don't know if Mordor has to be trimmed too drastically, if Gondor, Rohan and the Iron Hills are improved and the number of ports and coastal cities in Gondor are properly reduced. Mordor is in a tough spot even with strong units if the randomized starting points give him both Harad and Gondor as enemies.
I would probably go a bit further with making Gondor defensible and suggest one coastal city with a port in the south and just one other port to the far west for Gondor, and thread the bridge between Mordor and Gondor properly through the defensible city of Osgiliath. That's both accurate to the scenario and important for balance. Gondor could then easily reach Osgiliath first, and you can still attach a port directly to Osgiliath. It needs a fair spawn of course. Also, to alleviate Gondor's gold problem, their land should be rife with villages. That was the case in the original story, as with Rohan.
As it is right now, Mordor can take on Gondor and Rohan single-handedly. But when they are strengthened, Mordor's current strength may not be so overwhelming. As for Harad, I think KGB's suggestion of decreasing their spawn strength is probably fairer than mine of decreasing their available cities.
KGB wrote:I agree with Hatchfactor and LPhillips,
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Iron Hills needs the following things:
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2) To help the speed problem, place a move temple just outside the capitol, say 4-5 squares down the road toward the other cities. That way units can all get +2 moves as they start out from the capitol.
3) I'd switch Laketowns bridges to face the East (or at least the North). Right now it takes an extra turn to get to Laketown which sucks for the Iron Hill player.
KGB
One typo correction for clarification, and one note on the scenario: in The Hobbit (one of my very favorite childhood books), Dain's army from the Iron Hills marches exceptionally quickly over long distances, especially for dwarves. So it's accurate to give them a +movement temple by their home cities.
Anyway, this is receiving so much attention because we've all enjoyed the fruit of the time and effort put into the map already. Thanks for giving us this scenario!