A runner is rarely "sent" to second -- in Cohen's system or Polk's previous one either. The only time a coach comes into play on that is reading the ball to the plate/cutoff once it breaks the baserunner's sight plane -- and to let him know when a catcher is trailing/covering 1B. Basically the hitter/baserunner make their own read when the ball is in front of them, and coaching is only needed to help out with what is going on behind them. Now, once runners are rounding second, it's all on the 3B coach, and I think we're in agreement that Mingione has been a bonehead in that spot, and that our baserunning has never been good or even average under this regime. The primary role of a 1B coach in modern college baseball should be to pick up on pitcher/catcher tendencies, steal pitches, and relay them to the batter. You can do this with ~ 50% of pitchers/catchers from the 1B coaching box perspective if you clue in and really focus on stuff, even without scouting reports on that stuff...
Now, I agree that our baserunning has never truly been good in the Cohen era. Burroughs didn't do the boneheaded stuff at 3B that we have seen under Mingione though. And the mistakes we make between the plate and 2B is on practice teaching and game moxie which all ultimately falls on the coaches. That said, when you play aggressively, only the mistakes/failures are remembered by the masses. Few people remember all the extra bags Cody Brown and others swipe for us with good aggressive baserunning. They could, for all intents and purposes, succeed 80% of the time, and the other 20% a notable portion of the fanbase is going to melt down over.
I'm in agreement that there has to be new blood this year though. Just don't think it's time for it to be Cohen or Butch yet.