Actually Low run environment means the opposite, essentially the lower the run environment the more important it becomes to do everything yourself to score because your teammates will just let you down. Anyway this is a fairly simple empirical question outs have a certain value as does the advancement (which is context dependent but is about a 2-1 ratio of value). Baseball Prospectus breaks it down that including all baserunning events the Brewers are currently -0.7 runs. They break it down into separate categories of stolen bases, advancing on hits, advancing on flyballs, and other. They are above average on the other category and are excelling on hits. They are slightly negative on stolen bases, but have been quite bad losing over 2 runs on flyball advancement. I'm not convinced there is a particular pattern there at this moment that supports any hypothesis.