Okay let's examine Canaan. Since we havn't seen him play in the NBA, we'll go by his stats at Murray State.
But first, here's his physical measurables.
Height: 5'11"(without shoes)
Height: 6'0" (with shoes)
Weight: 188 pounds
Age 22
Let's look at his most recent season since it's the most relevant.
2012-2013
PPG: 22.4
APG: 4.3
TOPG: 3.3
RPG: 3.4
SPG: 1.6
FG%: 42.9
3FG%: 37.1
Now looking at his stats besides the points he's horrible for a senior point guard. HORRIBLE. But he averaged those points against pretty inferior opponents. He did shoot well from 3, though.
He got his team to a 21-10 record. Respectable until you notice that the league he played in was the Ohio Valley Conference.
Let's look at his numbers from his games against the best opponents.
Game 3 stats against St. Johns(a bottom of the barrel Big East team).
Points: 15
FG: 5-18 for 27.8%
3FG: 3-11 for 27.2%
Assists: 3
TO: 1
Not seeing the upside. Let's examine a few more games before we declare him inept.
Game 22 stats against Belmont(best team in their conference) but lost handily to Arizona in the tourney.
Points: 26
FG: 4-9 for 44.4%
3FG: 3-7 for 42.8%
Assists: 6
TO: 4
That is a much better game.
Game 31 again against Belmont
Points: 22
FG: 6-18 for 33.3%
3FG: 2-10 for 20%
Assists: 10
TO: 6
Rebounds: 9
In overtime of this game they lost with Canaan going 1-3 with 2 turnovers. So he had a good game until it mattered most.
It seems like his one talent is shooting the three ball at a decent clip. And as soon as he faced somewhat decent opponents he became an extremely inefficient shooter with a penchant for turnovers.