The pass rates for MDs are around 94% and for DOs around 80%. Not a perfect marker, but there is probably some general correlation with scores.
But I want to emphasize that scores are not everything. Even a high-scoring DO may have some problems matching, and this is where your school does come into play. If residencies choose residents from a certain med school, and they find out they are trained well, they frequently go back to that some med school because of a good track record. In that case, slightly lower scores from a known program is desireable to higher scores from a program they may not know as well. Scores don't necessarily correlate to clinical skills, so taking a chance on a high-scoring DO may be a risk compared to a safer choice. This does not mean that the DO is less qualified. However, there are only so many factors that the PD has to choose from, and they know that scores don't always correlate. And the result is that high-scoring DOs may be left out (it may happen to certain MD programs too, but less likely so since the LCME standards are more stringent than AOA- that's just how it is).
I still contend that individual effort does matter more than school choice. However, don't discount the extra little edge a school can give you. You have to take in many factors when deciding on a school (cost, location, curriculum, etc) and you should at least consider what effect the school prestige may have on your residency application.