The weakness for me in El Greco’s painting, a work which seems to focus on darkness of sin as rationale for the crucifixion, is that my eyes invariably are drawn to the loin cloth. The expression Greco paints on face of Jesus Christ further does not highlight pain or despair but some sort of bewilderment or resignation perhaps, a somewhat inaccurate depiction.
In Dali’s painting the focus is on the entire person of Jesus Christ, the loin cloth merely a detail. In the posture of Jesus Christ there is depiction of authenticity of submission to the will of His Father.
Dali’s painting is more representative of essence of the crucifixion.
I have to say then that you are right. While the themes differ, it is the details of the two paintings which really sets them apart.
Enjoyed your post.