I'm saying that it's far easier for them to take out an LEO satellite than an underground data centre, or even a surface one, in the centre of the US.

Are you saying it's not?

I'm saying I don't think Iran has the capability and the difference in capabilities between America and China on one hand, and Iran on the other is so different that I'm perplexed as to why they would even be mentioned in the same sentence.

I'm actually not even sure your suggestion is true. Theoretically they don't need to launch a missile and could attempt to infiltrate a data center instead. They're secure but not that secure against a determined enemy with any amount of real training.