User blog comment:Miskos3/Fairy Tail 525: Why Did the Emperor Never Love His Child?, Review/@comment-2214433-20170305095443/@comment-5303512-20170305184340

But it was later countered with Wendy smelling Irene's scent which has the same smell as Erza's scent.

Sting did say that if Larcade's scent was the same as Zeref's that would make sense. Sounded like he saying that between relatives and Parents, they have unique smells, but when it comes to a parent and child they are the same.

Also just because two people have similar scents would cause confusion that would make assumptions

Also the way Larcade worded it, he was artificial like Natsu.