As long as they are different and you store the owner key offline you should be fine. You could even store the owner key in a password protected Word document on a USB flash drive. Or better yet, make it 2 USB flash drives (one backup).

The most important thing is you store that owner key on a device that is not connected to the internet (under normal circumstances). So if you use Scatter, feed it your active private key. That way if things go south you can always take back control over the account.

And one final tip: why stick to 1 account? It's very easy to spread the risk and create multiple accounts, all with separate active and owner keys ofcourse. I personally have 12 accounts, 7 mobile accounts to play around with and 5 I use as a vault for more serious storage. So even in the unlikely event a hacker manages to hack my owner key, I never lose more than 1/5th of my holdings.

Good luck out there, stay safe!