What this means is that your targeting isn’t tight enough. This often happens in the beginning of trying to identify the persona.
Step back and ask yourself how else you can sub-segment your target market to tighten it up. See if you can have lots of short conversations with lots more people to help you sub-segment.
You will probably end up having several tighter targets, each sharing more nuanced attributes with each other. Now you can recruit a few people per target and look for the sweet spot.