I've always perceived both Striders as schizophrenic - it's their particular flavoring of what other people would attribute to ASD or ADHD (of which schizophrenia tends to share a nearly identical list of symptoms with) to me.. There's a certain je ne sais quoi about them. I know it's their personae, but maybe it's the flat affect? And the way Dave tends to structure his sentences and natter on is reminiscent of disorganized thinking and speech to me.