You are correct. 11k Germans.
But when you run the numbers, only 11k of 5,000,000 chance of being rounded up if you had 2 german born parents. And way more than 5 mil Americans had German blood.
Not sure, but I think FDR said any JPN heritage at all was grounds to be taken. Infants, kids, anyone. Not sure of percentages. But the EO was a blanket statement.