This is an interesting exercise. I'll take a stab and albaby can come along later to tell why my layman's perspective is wrong.

John deserved jail time. He did fail to respond to subpoena. He later tried to sidestep accountability by offering compliance in exchange for immunity. That the president subsequently asserted executive privilege is not a factor. It might have been if John asserted from the beginning that was his reason for non compliance but wthout the president actually doing so at the time, I doubt that would hold up.

George, who sounds a lot like Hillary, deserves jail time but we have previously discussed why her lack of intent excuses her from accountability under a poorly written statue.

Thomas could go either way. He should not have to testify against himself regarding the comment at the ABA meeting but he should not be able to use that as an excuse not to testify to the committee about other topics they may want to ask him about. I suppose he should show up and then assert fifth amendment based on the questions asked. So for not showing up at all he deserves jail time.