First, a clown does not need an anemone, just to clarify. They may well take to several types of corals in a tank, if you keep softies or LPS, but they don't need to have something.
But there really is no straight answer on this because anemones do have the ability to up an move, which means they pose a threat to animals in the tank (corals) that don't move. And there is no way to be sure that they will never move. So it is a risk you have to be willing to take, or not. Anyone who says they will be fine, has just not had the anemone up and move through their corals yet...or had it do damage. I've seen and heard both sides of the argument, but in the end, you just have to be willing to take the risk. That's all it is. The whole hobby is a risk.
FWIW, I would not call any anemone "hardy." Definitely need pristine water conditions and above average lighting to do well, which makes them more difficult animals to keep, IMO.