It's not surprising you were fooled. Midnight was intentionally a Spirit clone. Quality's publisher, Busy Arnold, was worried about Eisner being drafted. Unlike most of the other Eisner produced features for Quality, Arnold did not own The Spirit, Eisner did. Arnold could always hire other artists to continue Blackhawk, Black Condor, The Ray, etc, but if something happened to Eisner, Arnold could not just hire someone else to produce new stories. Eisner might have been gone for years, been killed in the war, or maybe their business relationship would come to an end. So in order to hedge against those risks, Arnold had Jack Cole create Midnight.
Cole did some great work on the strip. Eisner may have inspired that splash and the cover above.