It's been ages since I've played a cobless setup because they're bad but I've always wanted to play this one so I finally got around to doing it.
Sequence: C3-io, Ice | Cherry | Ice - Doom
I did not play this the intended way but I don't really care because it looks cool. The torchwoods are meant to be replaceable because you can't prevent damage but I'm scaffold so
This setup is a limit setup if you play it with the permanent torchwoods but if you play it with replaceable torchwoods, it works. If you want to play it with replaceable torchwoods, you would replace flower pot with torchwood in your seed slots
On wave 20, you have to place cannon fodders along column 7 so graves don't spawn on that column.
Reference: https://www.bilibili.com/video/BV1XQ4y167cH
Crescendo's 100f playing back in 2021. He played a better asymmetrical version in his video.