Germany didn't copy the US - they just happen to share similar roots.

Both historically had private hospital systems, and just so happen to implement pension/employer-based insurance programs very early on. German's just evolved in one direction and the US evolved in the other.

We copied the DRG reimbursement System from the US.

And no, we didn't had a historically significant share of private hospital systems, those came with the introduction of the DRG System, which forced many city/church owned hospitals into privatisation.

Before that, they had a "Fixed Price per Night" System, which also was a bit stupid, before that they got reimbursed their cost.