I went through all kinds of contortions with this.
First had them seperate, then I just linked them to a central site, a hub that had all these sites hanging off it.
That worked well for me, but I was told the SE would not like that, so then I made it all one site.
Before you knew it though I was reviving the other domains and resurrecting them with new content.
Now Gamesandcasino.com is the large site that really came to be what it is now as a result of a bunch of smaller sites, and I have all the smaller sites seperately anyway.
That’s just the way it ended up working out. I like it the way it is now.