If the sibling relationships in your book aren't like Thor and Loki in the MCU then you're writing it wrong. When writing you should go is this character a Loki or a Thor? Then base their interactions off of that. 

You could have a Thor and a Loki (The Ogs)

Two Thors 

Two Lokis

Two Thors and a Loki (Two siblings desperately trying to stop the other from getting in trouble)

Two Lokis and a Thor (Two siblings who team up on the other)

The possibilities are endless!