FF awesome looking dio's all of them and it's great that you are getting into dio's. The detailing is excellent the only thing that I would suggest and I hope I don't offend you is the weight side of things.
The xmas dio is perfect as you have the figures feet pressed into the snow and gives the impression of weight. With the dead trooper and the walker press them into the ground work this will give a better feel to teh over all dio.
For example the walker is a heavy machine so when it's feet hit the ground it's feet will sink a litlle depending on the type of ground. For the dead trooper he would have been there for a while so he will either be covered in ground cover from the elimants as well as being sliglty pushed into teh ground work.
Again sorry if I have over stepped the line as this doe not take away that these are still awesomem looking dios.
Ron