Pacers have a crowded front court with Zubac/Siakam and Toppin/Huff/Potter and likely Johnson and/or Brown being signed as 14th & 15th roster spots (Furphy also 6'8"). Jarace Walker has underperformed expectations and lack a true sniper off the bench. The trade for Isaiah Joe gives them one of the most consistent 40%+ shooters in the league over the past 4 years.
NOTE: I didn't include any draft assets for this swap, as I think the value is roughly the same (3-4 2nds). Please let me know in the comments if you think either team needs draft compensation for this move.
Wizards add a true on ball stopper that can cover up Trae Youngs shortcomings for only 4 2nds. If Anthony Davis can stay healthy, this creates one of the best starting units in the entire East: Young/Dort/Dybansta/AD/Sarr. They also have an incredibly talented young bench in George/Bilal/Johnson/Carrington.
Nets are just any team with Cap Space that can keep/cut both players for a couple 2nds.
OKC, even if they retain Kenrich Williams, only have 2 wings on the roster in Jalen (JDub) Williams and Kenrich Williams. This trade adds size with Defense and shooting on low volume, on a 1 year prove it deal for Jarace Walker. Since OKC only had $9.7m, he's the best option (others considered were Naji Marshall and Saddiq Bey). They also retain Kenrich Williams on a league min for $2.45m ($3.6m to Kenrich due to 8 yr Vet), sign a new deal with IHart for 3/$75m (TO Y3), and extend Cason Wallace for 5/$125m. This puts OKC at $220,778,048, under the 2nd Apron by $1.2m.
PG: SGA, Ajay, Topic
SG: Wallace, McCain, Stirtz, Oweh (TW)
SF: JDub, Caruso, Kenrich, Dix (TW)
PF: Chet, JWil, Walker
C: IHart, Sorber, Mara