From fangraphs write up in 2022 "On defense, Walker’s ability to bend and get deep into his legs, as well as his lateral agility and range, is incredible for a player his size. There have been some instances this year where he’s backhanded a grounder deep near the third base line and fired a rocket over to first base, but most of his routine throws are casual lobs over to first. There are some scouts who have seen nothing but this type of throw from Walker for entire series, and leaving them with questions about whether he can play third base"
looks like he wouldn't use his arm unless he had too, and that led to some scouts having questions about his arm - even though he playes short, 3b and pitched in high school and never had arm questions at all.
“Normally, when you have someone of his size and physicality, you’re seeing someone who maybe you’re starting to think of moving to the outfield,” Randy Flores, the Cardinals’ assistant GM and director of scouting, told MLB.com after the Draft. “But I believe that his actions, his grace, his speed is reflective of athleticism that positions him for the longest chance possible to stay on the dirt [at third base].”
Probably looking at average D, power bat 3B.