Well, the reason we traded for Morris is because we needed to shed Bradley's contract in order to sign Hayward. Ainge likely took the best player he could, while the Pistons made for a great partner because KCP was a free agent at the time. In a vacuum Bradley is the superior player, but the trade proved beneficial as we later lost Hayward and then traded away Crowder.
The 3 defenders we'll probably see most on James are Brown, Semi, and Morris. Using Semi on James is scary in that it allows James to not only rest defensively, but also play centerfield where he's able to play passing lanes and provide help defense. He's obviously a very intelligent player, so this is a concern.
These were the season averages of Morris and Semi vs the Cavs:
MPG FG% PPG RPG APG SPG BPG
Morris 25.0 38.9 10.0 3.5 2.0 0.5 0.5
Semi 18.7 .097 1.3 1.0 0.3 0.7 0.0
Quite simply, they need to be much better offensively. You can't have them play nearly 44 minutes a game and combine for 11.3 PPG and 4.3 RPG with dreadful shooting.
On the other hand, James has played and shot well vs the Celtics. The MPG are a little light than what we'll see because his minutes were limited in 2 of the 3 games (2 blowouts - 1W, 1L), so that hurt his overall raw numbers.
MPG FG% PPG RPG APG SPG BPG
James 34.0 53.7 24.0 10.3 8.3 0.7 1.3