Rather than the second coming of Jason Witten, I would prefer the second coming of Jay Novacek.
As much as I respect Jason Witten and his productivity, Novacek's receptions were far more meaningful in their timeliness. During the big games, in the most critical moments, Jay was there for that tough catch to get the 1st down. Witten may have been the better all purpose TE with his blocking ability and physical toughness, but Novacek was by far the better receiver due to his athleticism. He was an all state basketball player as well as in football, he competed in the Decathlon on an Olympic level, he was a competition level rodeo horse cutter. He sometimes lined up as a receiver.
As far as Njoku, I've read that the Browns are asking for a 1st round pick but they are highballing, they may go as low as a 3rd eventually. Still, I wouldn't go higher than a 4th. Considering our scouting department's success, that would be giving up a contributor.
When Njoku returned from the injury list the coaching staff was reportedly not satisfied with his effort or blocking. He was a healthy scratch twice. For some reason, they are distancing themselves from a recent 1st round draft pick in favor of others including this year's 4th round pick.
Besides, I'm intrigued with Blake Jarwin's potential as a receiving TE, he is also athletic like Novacek. Just like Novacek, if it is 3rd and 1, take Jarwin out, put in another O-lineman