Oh, I think I see what you're getting at. So swordbreaker will let him double attack red swords from range even if he doesn't have the speed requirement to double them, and it'll prevent red swords from doubling him if they get close (though he can't counterattack at that range).Just red swords. But yea it lets him double all swords so long as he has the health.
You asked earlier about Tome Breaker for Robin to counter Reinhardt. I do t think that is a good use of SP. Robin will always double Reinhardt because of Reinhardt's speed. Does Tome Breaker prevent Brave Tome from going twice automatically? Guess if it did that it wouldn't be bad.
I think my main problem is mass ranged teams because I have no real way to tank green or blue mages head on, so I have to spend a lot of effort trying to lure the AI into a bad spot while keeping everyone out of range.