I have seen all of the stats, including the 55 runs they scored in 6 games against the Reds, 49 runs in 10 games against the Cubs, and 33 runs in 6 games against the Pirates. That's 6.2 runs per game in 22 games against those 3 teams. In 35 games against other opponents the Brewers have averaged 3.2 runs per game.
I also saw the FanGraphs preseason projections which had the Brewers 20th in MLB in runs scored, and that was with Yelich having a projected OPS over .800. So, even if everyone in the lineup performs up to realistic expectations, I wouldn't expect them to be top quarter.
When I look at the current statistics for runs scored, I focus on runs scored per game, not total runs scored, for reasons that should be apparent. By that measure the Brewers are 16th in MLB and 11th in the NL. Being tied for 1st in the NL in HR while being 11th in runs per game says something about the offense being highly dependent on HR, which isn't necessarily a good thing.
The Brewers have a ways to go to be a top quarter offensive team.