I have some anxiety about a Siakam fit on this team. Yes, KAT will be more expensive, but you get what you pay for.
Siakam's 3P% is concerning especially if you're adding that to a lineup of Trae, DJM, and OO who aren't really the best at it either.
Both Siakam and OO are undersized too for the 4/5. They have some strength so maybe that will compensate...but I'd still rather have the 6'11" elite floor spacer.