Pillar keyword vs satellite keywords confusion?

Hi Guys

rookie question about keywords in pillars vs satellite posts.

I've read that you should pick a good keyword, write as thorough as possible authority post about that keyword and make that the pillar post for a silo.

Then go find long tail keywords relating to the pillar topic, and write posts based on those longtails, and do all the internal linking etc.

I've been told that it's not good to repeat keywords in multiple posts because it can dilute the authority of the pillar. E.g. let's say I have an authority post 'medieval swords' as the pillar.

Let's say people are searching for 'history of medieval swords' and that topic is really too big to include in the body of the pillar post, so I would want to make that into a satellite post.

On one hand 'history of medieval swords' is what people are searching on. On the other hand this longtail contains the main keyword, so is this satellite post going to have negative impact on the main 'medieval swords' pillar post?

What would you do in this situation? Many thanks for your assistance.