Update:
1. Greenskins are now treated as the southern stratosphere faction meaning that in snow regions they spread "snowy trees/their shrubs" instead of "snowy trees/their trees" and in temperate regions they spread a mix of "their trees/pines+some dead trees".
2. I made Wood Elves spread even more forest, because I reckon they have the magical power to spread them in snowy and desert regions. I gave them a special treatment to make them feel like they can spread the great forest everywhere. They still are going to have a mix of trees where appropriate, but not limit themsevles in their amount. Before I made them spread some grass in snow and desert, but now they just spread trees everywhere.
3. Because I was working on two working files I got something mixed up again and didn't see the error before. The Lizardmen were not spreading their jungle in the correct way. In temperate regions they just spreaded jungle for example. Now fixed, sorry for that mistake!
4. In Cathay all races spread a little of Cathay-based vegetation as well. Only around 25% though. It is not a normal mix that I am doing with other regions of 50/50.
5. Chaos factions (Norsca too) were spreading only "chaos/evil trees" in snowy regions. Now they spread a mix like other races.

Made an update as I have uploaded a version without Tomb King and Wood Elves changes by mistake. Now it's okay.

New version of the mod is here. Enjoy!