Guys, try to understand something about building teams. Each team has it's own separate set of needs, those needs are based upon a lot of things. My guess, is that the differences in these guards are smaller than you might think, but the strengths and weaknesses, ages, contracts, styles, etc are all unique. Teams usually have to try to choose not the best guard so to say, but the best fit for the plan they have in place to move forward. There may be a time when a team really is desperate for some size up front, so they might pass on a PG for a big. If they can grab a top level PG and somehow turn him into a big they do that, but at the end of the day, when you look at it in that light, it isn't always the guy you think that gets selected for a specific team.
The only time this isn't true is for teams that have cash, and have the opportunity to pick up a franchise guy.... those players come around once in a blue moon and you have to take them. As well, the draft, you get a great pick, maybe top five, and you take the best player possible.