as long as he thought he could save snape he did, but i think in book seven - after losing so much to voldemort he was also desperate.
But was forcing Severus to tear his soul and framing him with the Elder Wand really a good strategy? Albus' claimed reasons to have wanted Severus to be the one who killed him don't hold water. He could have avoided the damage to Draco's soul as well as an overly painful death by carrying some quick acting undetectable poison on his person. This would have also solved the question of the mastery of the Elder Wand. The purpose of the chosen manner of his death was that Severus be seen as the one who did it. Which was going to lead to his death if Voldemort were to seek the Elder Wand.
But was forcing Severus to tear his soul and framing him with the Elder Wand really a good strategy? Albus' claimed reasons to have wanted Severus to be the one who killed him don't hold water. He could have avoided the damage to Draco's soul as well as an overly painful death by carrying some quick acting undetectable poison on his person. This would have also solved the question of the mastery of the Elder Wand. The purpose of the chosen manner of his death was that Severus be seen as the one who did it. Which was going to lead to his death if Voldemort were to seek the Elder Wand.