Also, if they are 2 completely different businesses?

We are currently deciding whether to use a subdomain, the same URL or a totally new URL for our new marketing company.

We want to use blog posts that will get us visitors via SEO for both our marketing agency's website and our main website.

scenario 1)

Main website - kozyrecords.com Marketing website - kozyrecords.com (same website)

scenario 2)

Main website - kozyrecords.com marketing website - marketing.kozyrecords.com (subdomain)

scenario 3)

Main website - kozyrecords.com marketing website - kozyrecordsmarketing.com (slightly different)

scenario 4)

Main website - kozyrecords.com marketing website - examplemarketing.com (totally different)

What scenario is best to get the best SEO results from blog posts etc for both websites?