I think too much is being made of the strength of schedule. Does it tell you something? Sure it does, but what it tells you is incomplete. Strength of schedule, for instance, leaves out home/away splits, pitching match ups, quality of a team's offense vs. defense, and so on and so forth.
There's a stat that was actually talked about on MLB Now the other day (finally) that I think is a much better indicator of how well a team is doing. It's called 3rd Order Wins. What it does is take your runs scored and runs allowed and factors in, not the quality of opponent, but rather, the quality of your opponent's relevant pitching and offense. Afterall, there are some pretty bad teams out there who may be bad because they're lopsided (ex: bad pitching, but a quality offense). Think of it as a "weighted" run pythagorean win projection. Here are the projected standings as we stand today:
As you can see, as of this post, the Reds have a projected 3rd order winning percentage of .607, and the Cardinals are at an even .600. In other words, both teams are playing over their heads, but more so the Cards. Of course, the difference between .607 and .600 at this point in the season is only about a half game, so the two teams are basically on even footing right now.
Take it or leave it, I think these are two of the best teams in the league and they will be battling it out all summer. To be honest, anyone on here who think either side has been "lucky" is just fooling themselves.