Why are there such big differences in the size of the msp files if they are both all languages and why is the DC msp over 200MB and the exe is 150MB?

I doubt anyone knows, or even noticed. Adobe push a button, it makes MSP files and EXEs. They contain what they need to - what changed. MSPs are cumulative, so each time a new module or support file is edited, it will get bigger.

And you can see starting with the 2019 version it jumped from 98MB to 216MB!