I think one of these things informs the other. If Eichel and Reinhart are doing a lot of defending against other teams best lines it means we're probably defending more in general.
That means our more defensive D pair is probably seeing more ice time as well.
Dahlin's ice time is probably dependant on the success of our forward group. If we're spending more time in the offensive zone then Dahlin probably gets more minutes contributing to that offense.