For the most part, it's random in the sense that I just picked some numbers to assign value. E.g., copying the source sheets is worth 70%, formatting is worth 10%, etc. While it's looping through the source sheets, that part is calculated as the fraction of available percentage. So, if we say it's worth 70% total, and it's half done, then it will calculate 35%.
For the file, I would try to find the source of where it was exported from. I don't import userForms typically, but build from scratch. Reason for me is this avoids "ownership rights" when dealing with paid consultancy projects, and I've found that people tend to want slight customizations on each one.