A proposed mega-trade between the Pistons and Pacers
Detroit Pistons trade with the Indiana Pacers
These players may be available, but not necessarily to the Detroit Pistons, who have few trade assets to offer. It really depends on what the Pacers want. The report says they are in search of "more talent" and the Pistons do have a couple of plug-and-play guys in Bojan Bogdanovic and Alec Burks.
A trade like this works financially, but there is a big question of motivation for the Pacers to do a deal such as this:
This is a tough sell for Detroit, as those are three good role players and the Pistons are only sending back two, but how much run are Toppin and Smith going to get now that Siakam is on board?
All of these contracts are expiring or tacitly expiring, as Bogdanovic can be bought out and Smith has a player option that he will almost certainly decline.
Since these players don't have long-term financial implications, the Pacers would have to decide if these two veterans help them more now, and whether the addition of a second-round pick (albeit a good one) is enough to grease the wheels.
As for the Detroit Pistons? The decision would be easier.