Character issues don't make a young guy a good palyer automatically, so no, we do not "need" red flag guys. What may be argued for is that if a great talent falls in our way because of character issues, should it count or not... And this isn't really an argument - the ravens have drafted guys with baggages... There are certain baggage types that are a no-go in Baltimore, and that's why everybody knows that, for example, Joe Mixon won't be a Raven...
And just think about it... going with a guy you know isn't in full command of himself is no joke. Some of them, of course, go on proving that they have matured - like our very own Jimmy Smith for example, who was labelled as a potential trpuble guy - and that sank him down the draft order, tight to our roster.
BUT
For every Jimmy Smith, there is a Titus Young, an Aaron Hernandez, a Randy Gregory, a Rolando McClain, a Justin Blackmon, a Johnny Football, a Josh Gordon... guys who are known to be risky coming out of college - and then go on justifying any fears... Think about that too... not just the potential gain of getting a Lambo at a Prius price... Because it may very well turn out that the Lambo is broken beyond repair and you would be better off with a Prius...