I've got 11 at a bar, and have been doing it for 2 years.

Highest earners have been:

Ghostbusters
Metallica
Wizard of Oz
Star Trek
Twilight Zone
Addams Family

GB, MET, and WOZ have been consistently above the average for that location for 6+ months...and not tapering off at all.

I'll also add, if you're going to have a lot of machines, some are just going to earn more than others. If I replaced Fish Tales with MMR, MMR would earn more for sure. But would it bring more money into the room, or just take a little bit from each of the other machines?

I don't know all the answers, but no matter what you have in there, you're going to get a mix of high earners and lower earners.

The type of location probably matters, and so does the surrounding competition. Why will people play at your place? Is it their only option? Maybe your games play better than the competition? Maybe the competition has all older games so you are making a spot for the newer ones? Maybe there are several nearby venues that all have Star Trek...so give them something different.

Let us know how it turns out, and good luck!