Cason Wallace is easily one of the best defensive guard prospects in his draft class alongside Anthony Black, Ausar Thompson, and others, but rather than his defensive talent coming from using length and athleticism, Wallace’s effectiveness on that end comes from his outstanding positioning, rotations, and screen navigation. He's constantly disruptive on that end of the floor regardless of whether he's playing on- or off-ball and is likely the most fundamentally sound defender in his class.
His feel for the game undoubtedly appears on the other end of the floor as well, however, and it's most frequently on display when making plays for others. While I wouldn't classify him as a flashy passer in the same way Amen Thompson is, for example, he's a very capable post-entry passer, pick-and-roll pocket passer, and weak-side skip passer that won't force the issue if the right angle isn't there. And when he isn't able to connect with a teammate, he's proven to be highly efficient around the rim, shooting 64% on the season despite being an average to below-average athlete.
The path toward Wallace becoming a primary option on offense is a pretty unlikely one given his size and athletic limitations, but if he can continue to become more efficient in the midrange and from three, he has the makings of a very reliable second or third option on that end of the floor. I find it very hard to believe that there won't be at least one team in the lottery that would be willing to bite on such a safe prospect with a high floor.