Nope, the Crimson Wing is an AC6 DLC. More info here Su-33 -CRIMSON WING-
It's definitely Emmerian. The emblems used on the plane is similar to Garuda's. ('28', 'GM', Emmerian airforce emblem on the wingtip, Low-Viz Garuda emblem on the vertical tail.)
In Ace Combat 6, all DLC aircraft, except the specific historical color schemes always have Emmerian markings.
True, but if we're to follow the list of operators, Emmerian navy also used the su-33. Add to that the description in infinity about being used on airshows and "circumstances" made it combat ready is very fitting for a country like Emmeria.
Also, this