A few things mentioned...
Imbalance is USUALLY something to be avoided! Drano mentions a game where the imbalance is understood from the start and those who are disadvantaged do have other advantages to help make up for them. It can be fun but there must be ways to counter these imbalances and the Middle earth game Ruff mentions does nothing to make up for them, it's simply a bad game!
There ARE several Middle earth games in the variant bank, I have not played any but few look very good (aside from the concept that is). King Cyrus suggests it would be great to have a panel design such a game and he may be right but in my experiences designing games, it's far easier to simply design a game on your own, post the design and ask for comments/suggestions. It's really not too difficult and you need zero programming skill. If you can get a basic paint shop program and learn the most basic of skills on that program, you simply draw it out. You can find anothers map to start as your base and edit it as you like, once you get the basic game down, post your idea and watch the comments flow like crazy! Be careful to listen to all ideas but remember it's your idea and if you thought it out well, then others may not "get it" as well as yourself, take what others say, consider it and then use their ideas, alter their ideas or trash them altogether, you simply can not take EVERY idea as gospel! But do go ahead and start the process, I look forward to commenting when complete or near complete.