Hey Tom... Currently there is no function on WikiTree that will do that for you. The easiest way to determine if any relation exists is to contact Mr. Barhorst and ask him to use the relationship-finder on schmidt-931 and tell you what it reveals.
If that does not pan out, your only other option is to trace back the lineage of each person until you find a common ancestor and use a 'Cousin Chart' to figure out their relationship. You can find a cousin chart on Wikipedia here:
'Cousin charts' aren't just about cousins, they are more correctly called "Tables of Consanguinity" but that's a mouthful. Whatever you call them, they are very handy.
Good luck !