Henry isn't explicitly aged in ANY capacity to my knowledge, but hans is pretty clearly 15 going off his bio.
One COULD make a charitable argument that henry as 18, and frankly I'd accept it out of good faith, but hans its REALLY just an issue of "can you count? yes? hes 15 then".
its funny because steam forum peeps keep whining about the "1000 year old dragon loli" trope, but that trope at least just puts the age over 18, even if its a loli cope. KCD2 could of done the same putting the game 3 more years in the future but no, they refused.