The reasoning for not understanding boils down to a lot of German Shepherds do look similar in fur pattern plus it was not really something he thought about as it's not a huge known topic that Cecilia has children.
As for the cliche. I do agree I went for a bit of a cliche topic here since I did not want to hit super hard on too much given its only Chapter 1. I hope that the future plans I have will make the game overall seem less cliche once pieces fall where they need to!