Old Man Willow is a bit of an enigma.
Who or what is he? Was he ever an Ent - one that is hourning? Or was he always as he is?
Interesting it is, he sits on the very edge of
the Shire, yet we understand
Sauron was pretty much unaware of the Shire.
Whence then, comes Old Man Willow's ancient mailce? If not born of Sauron's hate, does it come from the very earth itself -
Melkor's "
one ring" and the deep corruption
Morgoth infused into
Arda itself? We read of no other
Ents Hourning, or Hourns, with such extensive power - or even having concern for anything much any more, other than as they are directed by the Shepherds to do things - like help at the battle of
Helm's Deep.
What then should we make of a 'battle' between, essentially, a malevolent old Hourn at best, and a Tree Shepherd?
If the very
trees/huorns themselves obey the Shepherds, and can move at great distances and speed when the need arises, would Willow's power be great enough to overcome whatever 'power' it is the Shepherds wield?
Treebeard vs. Old Man Willow... an interesting concept.
But given Willow's lack of ability to move about much on his own... (he seems he needs to draw his prey to him, vs. going to his prey) - Ent thinks probably this:
1. Treebeard would not be deceived by Willow's deceptions.
2. Treebeard would KNOW of Willow's attempts to lure.
3. Treebeard would not be caught unawares sleeping on a Willow root.
4. Treebeard would splinter Willow as he splinters stone (or worse) and Willow would become naught but matchsticks.
Naturally, the subject belongs in
The Great Halls of Speculation as we've no evidence one way or another, but... Ent roots for Treebeard on this one.