You are correct. A lot of people are thinking of it as having a CFII and CFI. You dont have to have a CFI to have a CFII. So think of it like that. Using some poeple argument then, if a CFII only had a CFII he wouldnt be able to teach in any airplane which, of course, is not true. Anyone with a CFII-Airplane rating can teach in any airplane they are rated to fly in. With a Com-SEL they can teach in a SEL with a COM-MEL they can teach in a multi, as long as what they are teaching is instrument.