female RTM helps your chances for sure, and 7x2 is not a bad tank size. Rocksor has a very good point, all-female would be much much more likely to work out long term. I'd say give it a shot and just proceed with caution. My general mindset with mixing any ca cichlids especially if mixing sexes, is that any combination is going to be temporary, and fish will have to be moved around, hence the other tanks. Sometimes you find a good balance after a while, and even then it can change down the line. Always a balancing act and can get tiring. But also can be rewarding and fun tank to keep. Good luck if you try it!
