Someone's probably already pointed this out, so if I'm repeating stuff already said, then just ignore me.
Three years ago it was January 2013. The 2013/14 season started in August last time I checked and Martinez took over in June 2013.
From your list, he brought in McCarthy, Barry, Lukaku, Deulofeu, Robles, Alcaraz ( Yea, I know ) McGeady ( Yea, I know part 2 ) and Kone.
He's also brought in Besic, Funes Mori, Cleverley and Galloway. None of these were around in Jan 2013.
He's also brought Barkley and Stones fully through into the first team, which would almost certainly have happened regardless of who was in charge, but they were very much on the periphery in January 2013 and Stones was only signed then anyway.
Of our first choice eleven there's still a core from three years ago of Howard, Coleman, Baines and Jagielka, but that's it. Howard and, to a lesser extent Jags are nearing the end of their shelf lives. To say the current team is much the same as it was three years ago is just wrong.