Rip at least had decency to act nice to his son and even give him some advice for a bit, but Runeard doesn't even have that, almost destroyed his own bloodline and his own kingdom, and his strategies were horrible as hell.

Yeah, the dam he built would've destroyed Arendelle had it fallen.

Runeard couldn't even keep it Christian

He's also a poor fighter and managed to lose to a Northuldran armed with nothing but a stick.