SOLVED: My UV inputs in 3ds were off. Sorry. That was a dumb mistake.
So I’m importing this model that one of my classmates made, and unlike all the other environments I’ve been using so far, the textures on this one are the wrong size (as in dimensions, not file size). There also seems to be no pattern with which these de-scale; some are larger that the source file, and some are smaller. On the source model I’ve applied the textures using a UVW Map Modifier, and have exported with embedded media to save the colossal task of having to apply these textures in unity. It’s also worth mentioning that my classmate has worked in inches whilst I’ve been working with metric, but I was planning on fixing that with some manual scaling.
Original texture sizes.
Texture sizes imported into Unity.