Clearly the OP doesn't get the concept of "all in" when trading for a player.
All in on Beal probably means moving one of the Jays, more parts for salary matching and tons of 1st round picks and swaps.
That is "all in" and that would not be a wise move.
Bradley Beal is no James Harden. That would be a crazy package.
In my opinion Tatum is on par with Beal if you take defense into consideration.
And if you consider age and contract length I'd say Brown is just as valuable on the trade market as Beal.
All in on Beal does mean that we're trading a ton of future picks + a couple of prospects (like how the Lakers obtained Anthony Davis). If another team tops that offer okay, but you're not trading Brown or Tatum!
I don't think the Wizards would expect Tatum or Brown in return either.
What team is going to trade a young All Star on a longterm contract for Beal anyway? I'd say none.
Tatum is not only more valuable but also flat out better than Beal. Beal is a very nice player, but he doesn't move the needle much at all (look at Washington's record through the years). For what it would take to acquire him, both in contract value and draft picks, he just isn't worth it. Frankly, I'm not so sure Walker isn't a better fit going forward (and Walker would have to go out to meaningfully make the salaries work and keep Brown and Tatum). If it was something like Walker and a couple of protected 1st's and a couple of pick swaps, I'd probably do it, just to try something new, but much more than that doesn't make sense and there is no way Washington wants Walker so you'd have to find a 3rd team.
I think this trade might theoretically work for all 3 teams, though New Orleans would have to believe in Kemba
Boston - Beal, Lopez, Bledsoe
New Orleans - Walker, G. Williams (or Langford), 2021 BOS 1st
Washington - Redick, Ball, Nesmith, Pritchard, 2023 BOS 1st, 2022, 2024, and 2026 BOS swap
I'd probably do that and it seems like reasonable value for all 3 teams if New Orleans thinks Kemba would work with Zion and Ingram going forward and Washington likes Ball, Nesmith, and Pritchard (as they wouldn't get as many 1st's in that trade).
So Boston post-trade
Starters - Bledsoe, Beal, Brown, Tatum, Thompson
Main Rotation - Smart, Langford, Ojeleye, Theis, Lopez, R. Williams
Deep Bench - Teague, Edwards, Green, Waters, Fall
That team would have a good shot at competing for a title the next 5 years or so.