Roman name for Danube

[abou]

What matters is that the Greeks had a way to represent (not exactly contemporary) the aspiration shown by the Latin H. So when you write it in the Latin alphabet, you include the H because that is how it was freaking pronounced. You don't include it because of aesthetics - you include it because that is how you properly transcribe the word. It's why Phi and Theta are written as ph and th, not just p and t.