We all know Brad looks at positions as ball handlers, wings and bigs. So there's easily space for 3 wings. But let's break it down to typical positions.
Brown primarily plays the 2.
Hayward will play the 3.
Tatum will play the stretch 4.
No problem.
There could be a bit of a problem depending on how the draft goes. If push comes to shove I see Brown on the outside looking in. Both Hayward and Brown can play SG and SF. While Tatum can play some PF he is more deadly as a SF. Like wise I'd say given their hight Hayward and Brown are more deadly at the SG position. So if we get the LAL pick this year our pick will affects how our team shapes up long term.
If we pick Michael Porter, then he will be our PF and Tatum will then be our SF leaving Hayward and Brown to vie for the SG spot. The same thing if we draft Marvin Bagley, as he is a natural PF in the Chris Bosh/KG mold. If we draft Mohamed Bamba or DeAndre Ayton then either of them would be our center of the future and Tatum would play PF, Hayward SF, and Brown SG. Because I don't see Hayward coming off the bench, I really see Brown playing more of an Evan Turner/Marcus Smart 6th man role going forward into the future.
On side note there are a bunch of UFA centers available this summer and I could legitimately see us making a run at Noel or Alex Len. So I think that Porter will be the pick over Bamba if we draft 4 or 5.
I wouldn't mind seeing this roster for next year:
PG: Uncle Drew! / Rozier / Shane Larkin
SG: Hayward / Brown / Grayson Allen (dare I say Danny Ainge 2.0)
SF: Tatum / Morris / Semi Ojeleye
PF: Horford / Porter / Guerschon Yabusele
C: Len / Baynes / Daniel Theis