For Poeltl, I think the Chicago pick and Collins would be the start of conversation. Jak doesn't provide a ton of surplus value relative to his contract, but Zach is well below. Probably depends on how much Toronto wants to gamble on certain pick conveying vs the protected pick that can become nothing. Probably ways around that in a 3 team construction where a team with sure assets (Brooklyn?) is willing to gamble for a better asset. We're probably not good enough for that to be sensible - might as well throw Bassey out there.
I think Backup Centre is sneaky important, seeing how Philly / Denver have, for years been dominant with stars on court and let down without them, with some of the Philly series (e.g vs Toronto in 2019) being lost on the weakness of the backup 5. I think it's probably 1500 minutes a year (15 mpg in 70 games that Wemby plays, 30mpg in the other 12). Collins has his deal for the next year and a half, so you're paying, after that I think you're looking for someone at about the level of a MLE player, and, someone who can be a genuine rim protector and space eater inside - I think replicating a bit of the defence is more valuable than keeping the offense as a 5 out system, especially if you're playing a bunch of wings rather than a two big lineup.