The more i look at Jarvan...

Jarvan' s role and quotes quite reflect the ones of Arthas while in warcraft 3: at the beginning he is a paladin and a prince.

Since dota uses warcraft 3 engine it used models and quotes of the characters, among them Arthas. when guinsoo ( that worked on dota allastars ) went to riot at the company fondation he riproposed the heroes in dota he worked on. Since they used the models and quotes of warcraft3, their characterization translated to this game too.

Now there is a lot of difference between J4 and Arthas, but the more i look at him the more makes me guess...

EDIT: probably because they share a quote: "For my father, the king". Done in the same exact way.