They wanted to know how the people felt about an institution dedicated for the spiritual growth of the singular self would co-exist with the civilians in this valley and what better way was there than asking them directly.
Seiya wanted to know if this would be a waste of time or if this was something they'd jump at if they knew the option existed.
It didn't seem that Mifuyu offered her own soldiers any chance to become stronger than they were and from what Shoichi told Yir, he claimed that they seemed to be slightly stronger than normal humans and it seemed to stem from their loyalty with Mifuyu if not due to another factor.
Seiya knew some people took to cultivation better than others and some people were simply born a bit more blessed than others as well but he couldn't leave this up to genetics and aptitude, if people wanted to get stronger and wanted a chance then he'd ensure they had this opportunity.