You're hinting they are similar with Lukaku in character? That's interesting.Morata is an intelligent player that can find space in attack and that is probably his main quality. He has flashes of brilliance but he is also severely inconsistent and does not really make use of his physique as he is not aggressive at all ( he is 1.90 ). He is a good support striker that can create and he is a pretty hard worker but he never really stood out. He was never really anything more than a backup striker, think Julio Cruz.
Can you really say he is a bad player ? No. Can you say he is a good player ? Debatable, most would say he is an ok player which is probably unfair since he can definitely contribute to the attack.
To me he seems an all around fragile player (mentally and physically) with great intelligence and technique. Sounds familiar ?
I think Morata is a more humble badge-kisser than Lukaku, that won't bring trouble on and off the pitch. Lukaku is the superior player on his day on the other hand.
Cruz >> Morata, though, you can't disrespeki Julio like that.