I don't.understand this affinity for trying to dispute things that others have done......makes no sense.
If I went by what someone else told.me, I wouldn't have tanks.
My tank,.right now and.for the past 4 years has about 12 black mollies, 3 goofish tetras, 2 blackskirt tetras, neon tetras, 2 chinese algae eaters, 3 cories, a timinekkii pleco, about 14 or so ghost shrimp, 6 danios, 3 tiger barbs, 5 oto's.....
They all live together happily, and have for many years. Everyone still has all their fins too.
This notion that you cannot do something simply because someone somewhere said so just....well....it's not good. I have had more issues with african cichlids than I have with the tank with the fish that ain't sposed to be in this water or that water. I even made a tank specifically for these cichlids, by reading what they say they need, and they all died off. When I stopped doing that, shoved some plants in there, and follow my feeding schedule, surprise surprise, they live on. I have a peacock cichlid that is in with a convict, and a jewel cichlid, and a.rainbow shark, and a.common pleco. Not one issue.
If we spend our lives doing stuff the way someone else said to, we stop living it the way we want to. Use a.little.common sense, keep them wet, and they will be fine. As long as you follow one principle when it comes to predators.....if it can fit in their mouth, it probably ain't a good idea to pair them up. Other than that, this hard water, soft water, this and that jive is just that. Keep your ammonia down, nitrites down and you'll be fine.