There are multiple families where the patriarch is a Paladin.
Crown Prince Arthas being a paladin and not being allowed to marry/continue his line would be a complete non-starter of an idea. For all the modern trappings, remember, the human kingdoms are … kingdoms as when that was the primary mode of government, beholden to all those rules. And there are even rare mentions of his own father being a Paladin. So… yeah.
Remember, the Order of the Silver Hand is a martial order first, a priestly order second. With some exceptions, Paladins were Knights, then they were Paladins (it’s literally the unit upgrade path in WCII). They are very often lords and nobles who would be expected, nay, obligated to maintain a family line.
Whether or not priestly celibacy is something common among Human adherents of the Light is one thing, but Paladins? All evidence says no.
Tirion had a wife and kids.
I think the Ashbringer did too.
Not sure, but I think Turalion married the void crazy windrunner sister (good luck with that one alliance!) at some point in those 1000 years of purging heretics for the god emperor.
If their not married then the light is on board with longterm affairs.
sigh The one day I’ve regretted switching from human female to Dark Iron. 
