Cleveland Browns would add Roquan Smith from Baltimore Ravens
You could argue Deshaun Watson against Lamar Jackson forever if you wanted to. We will go away from that and look to another spot. Mark Andrews is an upgrade over David Njoku, but it is not like the impact of adding him to that Bengals offense.
Beyond that, the Browns probably feel better about their offensive line at most spots. The Browns weakest spot on defense is the interior line, but are they going to go out and grade Justin Madubuike just for the need? Neither edge rusher is that big of an upgrade.
The Browns have young cornerbacks, and while Marlon Humphrey would be an upgrade, it may not be significant. Adding Kyle Hamilton over Grant Delpit would probably be looked at the same way.
The most significant addition is probably Roquan Smith. Jeremiah Owusu Koramoah is young and may end up showing more, but he has had some flaws up front, and Anthony Walker is average at his spot in the middle of the defense.
The Browns are weak upfront, and while Madubuike would help that, the stout leader upfront in Roquan Smith would be make the entire front look better. Also, the safety group and someone like Grant Delpit may finally see a light turn on with someone like Smith leading things up front. The Browns have Myles Garrett, who is all talent, but he is not the emotional leader who carries things in the middle of the defense. They need that and can get that from Roquan Smith.