If you have a tomato and a perc odds are they are not hanging together, so an anemone won't be the answer for that, more over the tomato will turn into an agressive booger and most likely kill the perc. If your yellow is trying to eat you peppermint than something is wrong. The only thing they usually eat is green algea type stuff. Nori seaweed etc...
My answer is simple. Remove the tang, and one kind of clown. Get a perc to match the first one, and hold off on getting anemone for a while. When you do decide to get one, maybe in about six or seven months, look into getting a tank propogated Bubble tip, check with your local reef club, I'm sure somebody props anemones or has some that split on a regular basis.