I think that Campbell and Walker are too similar to play next to each other. Neither plays downhill against the run, attacking gaps and taking on blocks. They're both more capable coverage players than McDuffie, but he brings an elements in the run game that they lack. Personally, I think Campbell has lost his athletic edge.
I agree it sometimes looks like the thumper (Isaiah) is the way to go and possibly when the Run game is a specific focus this all becomes more of an argument. However remember Campbell suffered 2 minor injuries this year. An ankle injury in Week 3 and a shoulder injury several weeks ago.
Campbell seems like he’s back healthy now and while some complain about a no call, what the underlying observation was there was Campbell was all over Kelce like a fly on poo p
He’s still intuitive and sticky in coverage and versatility more often trumps play in 1 phase.
McDuffie is great for a mid Day3 pick, but his ceiling is likely far less than Devondre.
I will say I’ve liked having that good 3rd LB that can come in without much dropoff (if any) against the Run (Isaiah).
I do agree with your point in overlap at iLB. We can use a post June trade for 8.875m cap savings. With possibly 7 draft picks by close of Round 4 I’d consider grabbing an iLB