We didn't do 30'000 trees there are 669 custom trees, which I personally worked a lot on, yes it is more than is noticeable but it is the small details of a map which can make it shine over others, the only reason not to do all custom trees is laziness but we weren't lazy and did them all.
Ninga to what you said about hearing from staff that Red Forest did more, a) I wouldn't really listen to rumours because most of the time they aren't true and b) both teams spent a lot of time on different aspects of the map, for instance Red Forest did the base cornucopia and the majority of the trees, while TE did the terraforming and detailing on the corn plus the awesome airship by ladyoflove which she put a lot of effort into, it may have taken us longer to do all the custom trees but TE still did a huge chunk of the map