You could put your autoblogs on the same host but personally I wouldn't because:
1) Autoblogs are known to be resource intensive and shared hosting might not be up to the job depending on how many you run on the same host.
2) Because hosts don't like high CPU applications (Autoblogs) there is a chance they'll suspend your account and if your main Website is also there it could be a major disaster.
3) Shared hosting is lets face it cheap I'd get pay for a second account and run my Autoblogs there why take a chance for an extra $5-$20 per month?
4) If you ever intend to link the Autoblogs to your money sites you'd want them on a different set of IP addresses anyway to hide the fact the assets are all yours (Also private registration would be good).
I never take any chances with my main Websites as I'm a coward

When you consider how much time you have invested in your sites why risk it for a few measly bucks.
If you're determined to do it make sure you have a full recent backup in case your host shuts you down. That way you can change hosts and get your sites back online as quickly as possible.
You do have backups don't you
