Do you think it makes any difference to the authority/value of a link from an external site:
If you own them both (but they are completely separate brands and identities)?
They are hosted on the same servers as each other?
Look forward to hearing any thoughts on it.
Not sure anyone can tell you with certainty but SEO tools certainly seem to think so. When you do backlink audits then links from the same c-class subnet (if the site is hosted on the same server, it likely has the exact same IP address), are usually considered more spammy Not wanting to go into the topic of usefulness of backlink audits in general, but there seems to be the belief that external links should be from different IPs (otherwise too coincidental and too easy to game)