Also, what are the main arguments for and against 2 country war or 3 country war? If a 2 country war has multiple fronts, I guess I don't see the distinction.
A three country war, particularly with the current "new" rules to win the war (must have fields of both enemy countries) is more dynamic. Though the odds are floating, no country will be permanently be the one that is piled upon. (Which happened for prolonged times with the old rules for winning the war)
When it's only 2 countries, it's always A vs B. It's a huge chance of getting unbalanced pretty quickly even with balanced planesets.
Planes that would have to be introduced before one could ever think about Axis v Allies:
- Ju-87 G and Hs 129 (counterparts of Il-2, Hurri 2D & B-25)
- He-177 and Do 217 (medium and heavy bomber, a He 111 wouldn't help at all)
- an Allied flack vehicle (Wirbelwind & Ostwind)
- Meteor (Me 262)
- removal (yes, removal) of the Me 163
Unfortunately, I don't see a good to balance the CV based planeset