My first tank was a 125 anemone tank (bubbles, ritteri, carpet, long tentacle, sebea, I have had them all). The problem you will have with multiple anemones is that if they are different types then they will start a chemical warfare within the tank. Also there is no guarantee that the clowns will host within the anemone. And 5-6 clowns in a tank with 2-3 anemones might work, but smaller the anemone, the less a clown will share with another clown. Then there is the issue with keeping anemones and the requirements for them.
What types of anemones are you thinking and do you have any experience with them?