Think about what you wanna do with that tree... I would op t for the widezone. That´ll minimize your opponent attack lanes and will make your 1-square dodge tactic even more effective... Less space to cover when he goes for the blitz through your lines...
hmmm. So the WE sets up for defense and the tree is in a widezone. Then the Undead sets up, and there are two widezones. What would stop the undead from marching down the other widezone?
Dodge 1 square away, and the mummy will blitz every turn. Nice to see that the woodies are still within range (you can't escape to mummies for long, so dodging away three squares in not a real option, 1 square is surely enough

). Nevertheless, meanwhile...
...the tree moves in turn one, maybe even turn two. Then the tree blocks in turn three and four, finally stunning a zombie. Then he moves again in turn 5. Impressive, I must say. The half nearly over, and he has been a real killer.

What a frightening monster!
By that time, you had at least three elfs beaten up at the line and five blitzes, includeing preferably 4 with a mummy. Autsch!
So I would put the tree rather on the line to soak up the damage, saving the lives of the elves. If he can stand up in turn two, he will again bind many undead players there, giving your elves more time and space to get the ball loose. Well,even if fouled out he still has the best chances to survive. A wardancer will break far more often. Better the tree then a WD, me thinks.
Sputnik
I won some impressive titles in 198X, some more in 199X, even more impressive titles in 200X, some of them REALLY impressive, and a few even MORE impressive! Not to mention a lot of less impressive ones.