The Piranha is for digging. Only. It tears out brush by digging it up. You use it going forward, I own a Piranha, but I don't have your kind of growth.
The ratchet rake is for raking. You use it mostly in reverse. It tears out brush without digging. It is a much neater solution for your type of brush. I do not own a ratchet rake.
It is POSSIBLE to remove a Piranha, but I sure wouldn't want to be the one doing it. I consider its installation permanent.