I would also recommend that you not provide either child with wrestling action figures or any other paraphernalia linked to wrestling. They will use the action figures to imitate what they see on TV. That's not imaginative, creative play--it's just repeating the senseless violence and shameful behavior they witness on TV wrestling.
When kids grow up watching endless hours of gratuitous violence, they do become desensitized to violent behavior, both as a perpetrator of violence and as an observer of violent acts. It's up to you to remove the addicting substance--in this case, take away this unhealthy programming from your children.