Bias plays no part in my opinion. If Markennan played for KU, wouldn't make a difference. Yes, his offense is much more advanced at this point than his defense but his shooting efficiency is extremely impressive and he is a stretch 4 in every sense of the word.
First off, chances are PHX lands outside of the Top 3, so forget Fultz, Ball and another of your top 7. Jackson or Tatum would be options but their main weakness is at this point they cannot shoot, particularly Jackson. You need to be able to shoot to make it in the NBA, that is Markennan's strength, that and his body is NBA ready now. You like Isaac better than him but your criticism that Markennan can't play defense because he is weak applies more to Isaac as he is listed at 210 pounds and a skinny 210 at that.
If PHX can trade up or acquire one of the Top 2 picks with a combo of Bledsoe and future 1st rounders then fine, grab Fultz or Ball, but Bledsoe has to go if Fultz or Ball are to be acquired.
I don't see Chriss having the frame to get much bigger, his body and skills currently are more geared towards a SF, if he can develop a consistent 3pt shot, maybe he becomes Rashard Lewis. But just as his criticisms in college (foul prone & lack of defensive rebounding), those are his main issues in his rookie year so far. Like I said, Markennan is more NBA ready IMO because his shooting ability is clear cut above Chriss and Bender and the other post prospects in this year's draft, if PHX lands around #6 then that is around the place Markannen will end up going.