. Blackbeard represents dreams not willpower which is why he has two broken devil fruits
Teach throw his Warlord title away, Doflamingo couldn't. Doflamingo was scared of Kaido and Admirals yet he was a conqueror despite being desperate for Warlord protection, Teach doesn't even need that. Teach being strategic has nothing to do with being cowardly. He even take the risk of dying when he tried to steal 2 devil fruits, attacks Impel Down and Marijoa, the guy take risks more than the people you think are brave. People like Mihawk or Crocodile wouldn't even dare to challenge Yonko, Buggy forced them you think they are braver?
Doflamingo sacrificed Monet for his goals as well. You are reaching as usual.