Imo there’s no design better than others. It all depends on your game. The tree you made looks like it’ll go in a cartoony game. It all just depends on what style you want to go for.
Your rectangle trees look amazing, though to determine whether it’s suitable all depends on the environment it would be placed in. If the terrain were ROBLOX bricks (smooth plastic), then those would perfectly fit in. If it were ROBLOX terrain, it may need some textures to better adjust to the environment.
Looks like you’re making a low poly game. Looks good for a low poly game game.
What does catch me off just slightly is this:
That wide space could probably be changed or add another rectangle within that one.