San Antonio would take on a sharpshooter in Trent. He is very skilled as a scorer and is capable of getting to the rim as well as consistently knocking down shots from deep. Trent would be able to fill Derrick's role on the team nicely and would provide perhaps an even more dangerous 3-point threat that's also an excellent all-around player.
Adding Achiuwa to this Spurs team would bring in more physicality and tenacity, especially in the rebounding department. He is a player with a high motor who's not afraid to do the dirty work. Still only 22 years old, Achiuwa has a lot of time to improve, and he could prove to be a valuable piece going forward.
There are several positives to take from this trade as well. If the Spurs choose to move on from Derrick White, replacing him with a younger, well-rounded scorer isn't a bad option by any means. A talented young big like Achiuwa would be able to fill needs in the frontcourt too.
I think many Spurs fans would like to see Jakob Poeltl remain in the silver and black. But if Toronto makes one of these offers, it will certainly be hard to turn down.