Basketball-wise, I agree.  Bradley is the most well-rounded player of the 3.  Both Smart and Crowder have serious deficiencies.
Unfortunately, Jayson Tatum can't be your starting 4 this season, otherwise a lineup of
IT
Bradley
Hayward
Tatum
Horford
would be ideal with Brown, Rozier first off the bench.
What the team needs is a legit starting PF.  Then your bench becomes Rozier, Brown, Tatum.  The younger players get the minutes they need.
Of course, I have no idea how to do that with the cap and other financial considerations.