I have stopped airbrushing enamels as I kept getting in a sticky mess, also I had more clog ups than with say Tamiya acrylics. However I still use enamels where I benefit from their slower drying times, such as weathering and painting around detail work such as decks etc. It does seem to be a bit problematic with uniform finishes, matt satin and to a lesser extent gloss, straight out the tin. However slightly thinned with a suitable enamel thinner, it seems to behave much better, using two or three coats to get a good finish.
I have found their new Satin White to be superior to the old version, requiring only a couple of coats to get a good finish. That may be down to how thick it is! As far as three different shades of green in three different tins, pour them all into one tin and stir, one big shade of green! Not a sensible answer, but then it didn't stop me doing it once!