Whether or not any of them were "loners" or poorly socialized, or even if Davis' speculations were believable, it would not change the fact that all four were products of the constitutionalist/militia/patriot movement.
If you don't know who Kahl or Matthews were, it really doesn't matter - they are well known to history and to the families of the people they murdered.
tHEN I GUESS THEY’RE NO DIFFERENT THAN ANY LUNATIC INDIVIDUAL AND NOT REPRESENTATIVE OF ANY MASS MOVEMENT, THEY JUST HAPPENED TO BELONG TO ONE?
Sorry, caplock, too lazy to correct. :)