Yeah I think it's ridiculous to say that you need to shoot a bunch of FT's every game to be considered efficient. Crawford ranks 115th in FTA's per game out of over 400 NBA players and shoots the league average in true shooting percentage. Please quit acting like the guy is on Austin Rivers or Brandon Jennings level efficiency. And looking at raw FGA per game numbers isn't really a good way to determine who's efficient and who isn't.
But whatever it really isn't that big of a deal. This is a low risk, high reward deal for the Celtics. They can only benefit from this trade. This is a guy that wouldn't even be in their rotation if the team was healthy and even with him in the rotation for the rest of the season, he won't be playing significant minutes. He won't get the same amount of touches as he did in Washington and won't be given the green-light to take as many shots as he wants like he did in Washington. This is a completely different environment for him.