Brandon Marshall may not have been diagnosed with Borderline Personality Disorder while in Denver, but he had a well-documented problem with immaturity, problems with the law, and at times was unprofessional in dealing with the Denver coaching staff. These were issues that Ireland definitely knew about, and gave Denver two 2nd round picks anyway.
As for Vontae Davis, read this analysis of Davis' before the 2009 draft (from nfldraftscout.com): "Negatives: Not a natural playmaker. Inconsistent hands for the interception. Doesn't fight through blocks with the physicality in which he comes up to tackle. Best in off-man and zone coverage where he can watch the action, plant and drive to the ball. Faster in shorts than on the field. Peeks back at the quarterback and savvy route-runners can beat him with double moves. Was benched in 2008 by coach Ron Zook, creating questions about his work ethic. Concerns that Vontae, like his brother, Vernon Davis, may lack the drive to turn his unique athleticism into NFL success." Hmmm....that sounds pretty familiar, doesn't it??? Again, these are character flaws that Ireland had to be aware of.
And as for Chad Johnson....well...any GM with half a brain wouldn't have signed CJ. He couldn't look good with Tom Brady getting him the ball. Enough said.