Game and patch game repacked-now smaller

[tone1]

I used Duxas repacker gui to do a repack of GT sport Game and GT sport Patch, Game was 40gb and patch was 19gb approx. After repack the whole thing is 19.8gb.
Am I doing it wrong, or is this how to merge the two together please?

 

[zvqyt]

It's not for merging. It's for making updates dumped on a different machine work with the base game.