I am a University of Kentucky alumni. Bias presented.
My initial assumption in this premise is that Derrick Williams, Enes Kanter and Kawhai Leonard are off the board. I believe each of them to be a better option than what is to follow if any are available. If it is the case that none of them are available, the Wizards are likely left differentiating between foreign big men Jan Vesely, Jonas Valanciunas, Bismack Biyombo and Tristan Thompson (Canada?) as the next most likely options. Each of these players has significant concerns, most notably that none are noted for being able to score with any consistency (not that a defensive minded player wouldn't be exactly what the Wizards need most). It also concerns me that the Wizards have not previously invested enough time and effort into scouting foreign players as a general rule. I could be misguided in this assumption, but I do not tend to read/hear about the Wizards as being as active as some other teams in their foreign scouting. Previous track records with drafted foreign players would seem to support this assumption as well. So, throwing darts at a foreign big with the sixth pick does not appeal to me.
These concerns bring me to the consideration of drafting Brandon Knight at #6. The Wizards are most certainly set for the foreseeable future at the 1, so drafting Knight may seem initially counter-intuitive or at the very least superfluous. However, having watched all of Knight's games, I can express that he is not necessarily a true PG. His court vision is solid, but not spectacular and his A/TO ratio is higher than desired. However, what he does bring to the table is significant quickness - both getting into the lane and on the defensive end, superb athleticism (demonstrated in the form of going for a dunk that he has no business going for and then getting rejected - also demonstrating fearlessness - http://www.youtube.com/watch?v=jrnhMcHjSKQ), and very good to excellent shooting.
The main con to this argument of pairing both Wall and Knight together in the starting backcourt is likely the defensive/size considerations. Knight is 6' 3"-4" and Wall is 6' 4"-5" (although surprisingly still growing according to recent comments by Ernie Grunfeld). This combination, while slightly undersized, is not extremely so. Russell Westbrook and James Harden are 6' 3" and 6' 5", respectively, as an example. I believe the combined quickness and athleticism of the pair can also negate much of any size disadvantage as well by being able to really get into their man defensively and fight through screens more quickly. There are also very few 2's in the NBA currently that have a strong post game that would cause further concern.
The benefits of this pairing include having two players that can break down a defense with penetration, a superb ball handler and passer as a 2 (imperfect PG skills become plus skills for a SG), the necessary shooting ability for a SG opposite Wall's current lack there of, and two very strong leaders with high character in the backcourt. The last skill I, and purportedly Mr. Leonsis, believe is very important. Knight is not the vocal, aggressive leader that Wall is, so I believe that the two could easily co-exist without butting heads. But Knight, from quotes from John Calipari, may actually be an even more diligent worker in the gym than Wall. Wall has said that he needs someone he can "go to war with" and a player that works equally/exceedingly hard in comparison to him seems to fit the bill. Knight is also extremely intelligent (as evidenced by his 4.0 GPA and sophomore standing in college after his freshman year) and capable of taking/making a big shot (as evidenced by both the Princeton and Ohio State Games in the NCAA tournament). Knight, Wall, and Jordan Crawford could all play together as well (two at a time) and could form a guard rotation where very little is lost when any one player is out of the game as each players skills seem to complement the other's.
With Knight in the fold at #6, the Wizards can look for a role player at #18 to fill a role at the 3/4 position. Chris Singleton, Kenneth Faried, Tyler Honeycutt, Jordan Williams, Trey Tompkins, Tobias Harris, etc. seem to fit that description to varying extents. These players seem to posses many of the traits of the foreign bigs likely to go in the top 10, but there does not appear (to me) to be a player with similar skill/character to Knight at #18.
I ran this scenario by my fellow UK fan brother and he did not approve. So, I had to invite others into the discussion to see if he's right and I'm just being a biased UK/Wizards fan. Should Knight be an option for the Wizards at #6 with Kanter, Williams and Leonard gone? Or, would the selection of Knight be repetitive and the potential of the Wizards getting their pick of the litter for foreign bigs too much to pass up?