Apparently, there was a third brother - I was wrong in assuming there wasn't. Both Stanley and Stanford are the kids' great uncles, while "Shermy" (supposedly the child that appears in their mother's arms in the flashback, or an older brother we do not see) is the grandfather. Near the beginning of the episode Stan…

Stanley (the fez-wearing money grubber who runs the shack) is supposedly the grandfather. When they get sent off to their "Grunkle Stanford", they are being sent (supposedly) to the author of the Journals, the real Stanford. This was confirmed in the new episode's trailer. When his brother went into the portal,…