I think Koufos is a very good bench player to barely adequate starter. He would be a minor upgrade on the Celtics current options but not an answer to anything long term.
Which is why he would be a very good pickup.
We won't commit a long term plan for him, but at the same time, he'll be an upgrade with very little downside. 3 years/$18 million sounds about right, a pay raise and starters minutes.
It will also create competition within the club with Tyler Zeller, which would only make both of them better. And alongthose years, we could easily figure out if he can be part of the team.moving forward, all while having, as you said, an adequate starter and a very good backup.
Win - win if you ask me.