Why I Am Bad At Phonological Analysis

Just a quick note about phonological analysis, I almost never think to use a sound that doesn't appear in a language as the template for a distribution of different phonemes. I've seen the contexts where it really seems to work well, where there is an unusual gap, but in a lot of cases it feels like drawing a line around the exterior of the maze, and claiming that not only did you figure out the maze, but you have the most efficient method.