Not sure how to make this more realistic, can't extract shadows due to detail, mockup

[Adam34311780qa2t]

Hey everyone,

Just a little help if someone can shed some light and explain how to. The original is in the post aswell as the edit and the PSD file.

Description of the problem:

Created a mockup image of a man holding cards, I made smart objects and added wide cards into the picture, it looks REALLY weird. I can't use the multiply and screen trick to add shadows and brighten because of the original cards complexity.

Initially my idea was to make those cards blank but keep the shadows which is above my skill level at this moment. They are also slightly different sizes due to using wide cards. Though It looks like in the original image the cards are all different sizes now. Does anyone have any ideas how I can make any card I insert look realistic?

PSD file with original and edits: 3 Items

Any feedback or posting a psd back to show is welcome!

If I can fix this I can make mockups for my own designs more easily, not just cards.

[Adam34311780qa2t]

Or if possible, a way to make the cards blank without removing the shadows and highlights.

Or a way to make realistic shadows (i can always mask out the cards for other ones).

Then i can do the rest.

I'm finding it really hard to transfer shadows and highlights off an object with lots of detail (like a card with detail on it). If I knew that I wouldn't have a problem here, tutorials everywhere only covers shadows on background. The problem is, if there's any black in the image behind the shadow it doesn't really seem possible to me.