I posted that comment on the wrong guide. I meant to post it on another guide for the cactus item that had a different method. did it on mobile while doing something else so just made an error. my bad, your guide is good!!!

It's absolutely the same, but ok, why not.

I did it with Bush because you can disable autoaim on the sniper rifle with right click. That allows you to pick defensive tomes and run backwards into the cacti. None will be shot unintentionally with your weapon that way. That avoids the need to break the Athena shields in order to be able to touch anything. Shotgun as a second weapon is good because it can also be switched to manual aiming.

You're absolutely right. But I chose Athena because she gives +thorns per level and because her weapon doesn't passively attack others. If you use someone else, you don't have control over her attack and might not be able to kill the cactuses with Thorns because your weapon will be killing them. With Athena, you've used up 2-3 of her shields and are starting to kill with Thorns. But, of course, you can use anyone else. It's up to you.
But as I wrote, I got between 30 and 40 cactuses kills in one run, and with others, I couldn't get more than five. So, I'm just describing my experience.

Cheemse is right, doesn’t work with Athenas Shield when blocking the attacks. In fact, anyone except Athena would be better.

The problem is that athenas shield doesnt do thorns so it doesnt count as a thorns kill...