What I do in low level dungeons is pull first, then mark. I cycle through the targets after the first or second flash, see which one a DPS has the most aggro on, and mark that one. Most DPS will ignore marks in low level dungeons anyway, so if you're going to mark, you might as well at least make it look like people are following your orders by telling them to do what they're already doing xD Then you can mark another with 2, and maybe they'll attack that one next. There's never a need to mark the last target.

In addition to marking after pulling, you can also mitigate this problem by leaving a fight before the last mob dies. Wait until it's at ~10%, and then just run off to the next group. The DPS will be too busy attacking the moving target to pull ahead of you.