I mean, unless you type it completely out of order, you'll spell "Johann" while typing out "Johannes," so it shouldn't particularly matter that much overall.
In German "Hans" is a nickname for Johannes, not an independent name. Same goes for "Jan" (or , again, "Hans") in Dutch. They are nicknames for Johan. Much like Jim is a nickname for James.
"Hans is a masculine given name. In German, Danish, Dutch, Faroese, Norwegian, Icelandic and Swedish, it was originally short for Johannes (John), but is now also recognized as a name in its own right for official purposes." -Wiki
Eesh, I got Johan as my first answer and then went "Hmm, Hans, maybe? Nah, I can't find any similarity at all, why bother trying..." ARGH. yet I guessed Giovanni, Ivan (got that one mostly because one of my Great Uncles was named that) and Sean....
Eoghan (Eoin) is actually the original Irish version of John. Seán is a more modern adaptation based on how a speaker of Irish Gaelic would pronounce the word "John".
I tried Shaun and Shawn, thought they were the original ones of scotland or ireland or welsh. So after sean showing up, I thought well then the other is one of these.. never thought of things sounding like Ian.. Did think of siobhan! Was very proud of that, but alas didnt make it (yes I knew it is for girls)
Johann and Hans are both shorter versions of Johannes. I tried this as this is my own name, kind of confusing that they are distinct names in this quiz.
https://en.wikipedia.org/wiki/Ewen