They scored 5-2-5-7-7-6 runs over their last six games in April. 32 runs over a six game stretch is 5.33 R/G, well above the MLB average of 4.31 R/G. The offense didn't really turn putrid until May so coming up on four weeks.
These things tend to go up and down throughout the season. In April they scored the 4th most runs per game and went 16 W - 11 L. So far in May they've scored the 2nd fewest runs per game and still managed to go 12 W - 13 L to this point, pretty remarkable really.
I don't think anyone believes the Brewers have a Top Four offense in baseball, though plenty seem to believe they do in fact have a Bottom Two offense in baseball.
I think the truth lies somewhere in the middle so I'd expect them to perform better in aggregate over the remaining 106 games than they have over the last 25.
Then again, if we go back to May 18th (first game after the four shutouts in five games) they have scored 5-5-5-4-8-5-1-6-3-5 runs for 47 runs in their last ten games during which they've gone 7 W - 3 L . . . so maybe it's already begun and the true putrid stretch was really only like 2.5 weeks from May 1st until 17th (& the four March games of course).