All three of these people have 5 strength; the highest strength (I'm pretty sure) on unique characters/non-army characters (except Balerion… who's an ancient dragon). Now, I can easily understand why Ser Arthur Dayne has 5 Strength; he's the Sword of Morning, arguably the deadliest knight in recent Westeros history. That said, how is it that Rhaegar, the crown prince prior to Game of Thrones, has 5 Strength as well. To my knowledge, it was never stated that he was super skilled at fighting at least on par with Ser Arthur Dayne (which brings up the War Crest icon too, but whatever).
Rhaegar can slide in contrast to Craster though, which for some reason, he has 5 strength also… I don't remember him being overly awesome in terms of combat or anything else. I know he likes axes but does he deserve 5 strength? And why does he have such high strength for a unique character?