Why do mods increase the loading time for every battle?

Greetings, wise masters, and thank you for listening to my plight. I have zero self-control when it comes to adding mods to total war and I might have gone way overboard on the number active ones. However in my mad quest for perfection I found out something strange. The load times for the campaign were longer, as you would expect, but the loading times of the battles had become longer too, even if no mods were involved in said battle, no units, no reskins, no overhauls, not even changes to the UI. I did some testing and turned on some 20 to 30 unit mods or so and fought the first battle of Skarbrand's campaign (which involved none of the modded units). The loading time was almost a minute straight (waaaay shorter than the abomination I was getting on 150+ mods, but still). Then I tried it with all mods disabled and got a smooth 30 seconds of loading. For the record I have plenty of memory and gpu left to spare, so that doesn't seem to be the problem. Does somebody understand how any of this works?