Two Red XIII questions (minor spoilers)

[MJN SEIFER]

Try not to read his name as "Red the Thirteenth", but as "Red Thirteen".

I already do.

Here's a thought though, (if you want me to move it I will);

If he was marked as "13" does that mean that others of his species where captured too? I doubt it's the same number marking as the Sephiroth clones as they are all humans.