I always thought a good split would be...
Harad and Duns go free
Corsairs, Easterlings Rhudaur go DS
QA is removed.
Kev
RD: Why? If you're going to put forward a counter-opinion, let's see the
argument to back it up, as I have done.
Well Richard, as you asked so politely, I'll furnish some details. 
You said, "Normally FP get Duns and Cor whilst DS get Rhu, Har & Eas".
I don't think this is the case? The Easterlings usually get removed.
You suggested a 13/12 split in favour of the DS. I think this is unfair
given the strength of the DS traditionally in winning games. Giving the
side that wins most games an extra 42 orders per turn seems very unfair IMO.
Therefore, make it 12 v 12.
You can remove the Easterlings as normal or, as I propose, remove another
nation.
In a normal 'grudge' game, Harad (usually) gets attacked quickly by the
Freeps. The Corsairs, SG, NG (and to a lesser extent) Sinda (usually) make
Harad the first target and it usually doesn't stand a chance. In the team
games I've been in, Harad is overrun by turn 10.
Therefore, make Harad go Free. The Free have a better economy than the DS
at game start so giving Harad to the Freeps isn't much of a bonus to their
combined economies.
Instead, make Corsairs go DS. A Corsair v Harad battle is a lot of fun at
the start. The Corsairs are more isolated than Harad, they also have the
advantage of having the biggest navy, so the freeps have to be careful when
trying to invade by sea.
If the Easterlings are given to the DS, they can send Cav armies from their
capital and from 3538 to support the Corsairs. (Who will, admittedly be
hard-pressed).
Also, the LoR (3230) and CL (3630) armies have legitimate targets to go for
in Harad.
With the Easterlings and LoR armies in Rhun, the Northmen/Eothraim can't
send as many troops around the back of Mordor or to Morannon.
Most DS teams would *probably* prefer an Easterling Nation to a QA nation
(cue howls of outrage from everyone telling me the QA is THE MOST IMPORTANT
nation). 
I just think that to maintain fairness it must be 12 v 12. The QA was the
obvious (to me) nation to eliminate. It offers +40 emmies and double
scouting. The Dragon Lord does double scouting as a special nation
ability. Is it really that important to the DS cause that a nation can
name +40 emmies?
Anyway. It's just a suggestion. Richard, I'm sure if you can convince
Harlequin to do it, and you get enough people interested, you'll get your
13v12 variant off and running. Similiarly, I'm sure if Laurence can get
enough players to play his 14 v 11 variant that will be off and running as
well.
Just my opinion Richard, I won't mind if you don't agree!
Would it be an idea for a 10v10 Freep v DS team to take it in turns to pick
the nation they would like? Harlequin could toss a coin and decide who
went first?
(Or is that just a totally mad idea)? 
Kev