The following may come as a startling revelation.
Contrary to what you think you saw at the end of season three of The Wire, Stringer Bell was NOT murdered by Omar Little and Brother Mouzone. This is by no means a suggestion that that scene was some sort of dream, but rather that Stringer indeed survived the attempt on his life. You see, as his imminent downfall became blatantly obvious to him -- between his flagrant double-crossing of trusted cohorts and his making enemies with just about everyone whose path he crossed -- Mr. Bell began taking precautions he wouldn't have otherwise needed. One of these, inevitably, was his wearing of a bullet-proof vest everywhere he went. On the day of his 2004 "murder," his paranoia effectively saved his life. So he did the smart thing -- he played dead. And, having friends in Baltimore's high places, he was able to smoothly carry about this ruse. No one knows precisely how he did it, but there are a number of possibilities, mostly involving the bribing of drivers and morgue workers. But c'mon, the dude was loaded.

The next thing Stringer Bell had to do was lose Stringer Bell. This entailed changing his name, cutting off all ties, and getting the hell out of Baltimore. With his new name, Charles Miner, he moved to New York City where he laid low for a period of five years, working odd jobs to stay afloat. He falsified his documents under his new identity -- driver's license, Social Security card, et al. -- and after enough time had passed, he began to seek higher-level employment. He made a false Bachelor's degree and an MBA. Eventually, his skills were sought by Dunder Mifflin Paper Company, whose ex-V.P. Ryan Howard left a large vacancy in the corporation's upper management. Bell/Miner interviewed for the position. His fake resume was most impressive to C.F.O. David Wallace, who was particularly interested in his stint at Satacoy Steel. (I know this company is totally fabricated because unlike Dunder Mifflin, it doesn't have a Wikipedia article.)

Charles Miner was hired in early 2009. Though his degrees were forgeries, his extensive business background working in the Barksdale organization as well as his stint at Baltimore Community College rendered him equally qualified. In his new, more legitimate profession, Miner has been using the same tactics he used in his Stringer Bell days -- the same deceit, the same eye at upward mobility.
I feel the evidence I've provided is conclusive and irrefutable. As for Beadie Russel and Holly Flax being the same person...well let's just say that's a discussion for another day.