I'm going to be completely honest here WKA, your models are amazing. The time and effort your putting in to make this themed army should be noted, but I fee you painting is somewhat letting down the models. The extent of this is minor though. Your colours seem to be fine, but simple techniques like highlighting will really make your models pop. And it's not like you have a deadline, so take your time, go back over your models and touch up places were paint has slipped onto the wrong surface. This tidying up will make the model look alot more tidy, making it look better again.
I'm also going to echo the comment on an airbrush for the tanks to minimise brush strokes across the larger surfaces. Also you can use it for your troops, to get consistent colour across the units, re; the two Sang. Guard been one darker than the other.
This is no means a way to bash your efforts, but to provide some constructive critisism of your work so that you can improve.
Keep it up bud,