My Mom was a seamstress. I grew up watching her create thousands of articles of clothing............I understand the process.
Patterns are all basically the same in how they are created. They are in seperate templates such as left side, right side, collar, and sleeve. The templates were cut from the pattern. These templates are pinned to the fabric in a nesting manner to utilize the fabric efficiently. The fabric is then cut out around the pinned templates pattern. The templates are only removed at the time that the fabric was to be joined (sewed) with another piece. The two fabric pieces were then pinned together and then sewn together on the machine.
The templates on the patterns are never joined together. So I'm not sure why you would want to do this.