Let's put it this way....
We all know we're a few years away... No matter what we do.. No matter what signing or trade you think are out there, it will not have us competing with the Warriors. Not in the near term at least. We have to wait until the Warriors core has been together long enough that it forced them to have no bench, losing guys year after year because of paying everybody max money, and we see them start to tail off.
If you look at Lou Williams, if you don't trade him this season, then next season you pretty much are forced to. If not he becomes a FA going into Age 32 season. If he plays at this level next season, that pay check isn't going down, especially now that the cap is $30+ mil higher than it was when he signed with us. But let's say we don't trade him, he becomes a FA and we want to sign him.. That's $10mil+ cap that is tied up that could be used in guys who are younger, fit better, or may be actual star players. When history shows, age 30 + for a guy like Lou Will tends to be a negative.
Too much of a risk not to see what is out there for him .
Now if you traded Clarkson for an equal prospect somewhere else that may fit better, then you covered your basis a bit. But still worrisome to keep Lou for that long.