Twins are considered two people. You may edit them slightly so you can RP them better, but they are still two people. Two different minds, two different opinions, and two chances for posts from two different perspectives. I'm sorry, but they really do count as two. Your other characters may have a chance to join the RP in the future, as we may be more settled in the future. At that point, we may also have less RPers, and may need more characters. But, until then, you will have to settle with two. If you have other characters running around at this point, we can say they have disappeared, if you wish to salvage them, or kill them for shitz and giggles (If you want them dead of course.)