Here's Glenn More, a writer for Fansided:
I won't break down the potential of the Cavs offense. Zach Lowe did that today and he did it exceptionally well.
But I will add this wrinkle. Allen is not the 3-and-D wing player the Cavs could be looking for. He's 39. The man simply cannot stay in front of most NBA guards anymore. But he does create some fascinating options on offense.
Allen will join Mike Miller, Shawn Marion and Tristan Thompson on a quickly developing second-unit. With Dellevadova taking the helm of that unit, presumably, we can expect to see a lot of small ball. Thompson will likely assume the role of the 5, Marion the small-ball 4, then Miller at 3, Allen at 2 and Dellevadova at 1. That squad might be able to beat Milwaukee's starters. It could definitely trump any lineup Philly trots out this year.
If Cleveland adds a 3-and-D swingman it could also provide further depth and rotation options. Coach David Blatt's system will likely be a hybrid Princeton set up. There will be a ton of pick and rolls and down picks. There will be a lot of motion. This offense should play at a near breakneck pace.
Adding Allen keeps a defender on the perimeter and away from the paint. Plant Allen in a corner and watch the driving lanes clear up a bit. Running him with Thompson-Varejao units could provide some breathing room (even if it is marginal). He could clean-up as a trailer on fast breaks. He's a unique offensive talent and his presence could add a few more wrinkles to the system.
All that said, I don't think he's a threat to start over Dion Waiters. Waiters has gobs of potential, which might finally be realized under Blatt and James' tutelage and he has young legs, legs that might eventually be trained to perform defensive rotations.
Now, the addition of a true 3-and-D guy could push Waiters to the second unit, something that seems almost fait accompli at this point. But Allen is not the harbinger of that fate. He's a fun addition to an increasingly impressive roster.
Let's hope it's real (looking your way Glenn Moore).