I don't think Wall is nearly the player Westbrook is, on the whole. However, Westbrook was an absolute liability in the playoffs. If Westbrook were a younger player and inexperienced, okay you get a pass. He's a former MVP and been in the league 10+ years, you gotta be earn your money when it matters.
Maybe Wall won't help win as many games during the regular season, but he will at least require teams in the playoffs to guard him. We should be building the team with respect to how it'll help us in the post-season. Westbrook is just not a post-season guy.