I agree, eat roo.
Heavy, hooved animals place a lot of weight on a small area which compacts the ground and makes it difficult to grow plants. To turn cow paddock back to forest you have to turn the soil to soften and airate, before you plant out. This is the problem with cows, horses and sheep and pigs.
They stuff the environment at every turn.
Go for a drive down the Hume Hwy, or up around Gloucester and marvel at the "beautiful" farmlands, millions of hectares of dead, brown grass with not a tree for miles. Oh yeh, and a cow every acre and a half.
Now roo on the other hand, you dont even need fences, they don't even need any human intervention. Beautiful thing the old native animal.