eh, I like the story.
even as an Isekai, their life is felt actually at stake. (well, we know those girls would probably will not die but, oh well), we see that MC taking this seriously, his knowledge is OP in this world but it's not like he actually know which one is working. He can do trial and error, but the error's risk is rather high this way.
the OP ness of the MC was properly explained, so it's not felt randomly gained like those typical OP MC that suddenly get OP.