1. Ayub Khan, 2. Mohammed Azmath, --3.Azmath/Doe ---4. John Doe #2
Maybe you are looking at picture #1, on the far left, of Khan, who was Azmath's companion on the train. The picture that is in color is Khan's and it is attached by the source I got it from to picture #2 (second from left, in black and white) of Azmath.
I am ONLY comparing the three pictures on the right. You're right that in the picture on the far left Khan's eyebrows are different. Khan's eyebrows are similar to those of a lot of the guys in the pictures at the FBI. Azmath's eyebrows are very different than those of all the other guys. That was exactly the point I was making when I originally said Azmath is John Doe#2.
I did not change anything when I merged the pictures. I only made the picture of Doe#2 less opaque when I placed it over the picture of Azmath so that you could see through it somewhat.
I wish I had better computer skills so that I could do it in a way that would illustrate the exact match of the eyebrows (like having one man's eyebrows in red, and the other's in green or something.