Yes, you have to be the owner of all of them.
What I meant was that hosting of all the sites needs to be at the same place.
You can’t have one domain on EngineHosting, one on MediaTemple and one on Dreamhosting.
Many of my sites are on a stand alone box using cPanel. cPanel allows me to create addon sites pretty easily.
With EngineHosting, they’ll add it for you.
MediaTemple’s GS works fairly well with adding domains.
DreamHosting I have no, clue, haven’t used them in years. 😊
Here’s an example.
I have a site called myname.com. I have a site called granddaughter1.com, daughter1.com, and granddaughter2.com
(The other sites are EECore now, since I don’t need them to do too much.)
But in the folders on my site, granddaughter1, daughter1, and granddaughter2 are directories on the same level as my system directory.
So when I create my path.php files for the other sites, I can use ../system which works for finding the system directory.
On MediaTemple I do something similar.
Make sense?