my preference has always been to have (at least) two of every species, unless there are known issues of intra-species aggression. As to whether it would lead to them being out more I suppose there is no way to know for sure other than to try it and see. It seems likely to me based on the shrimp I've had but there are always individual differences. If nothing else you would have twice as many chances to see them in any event.
I don't know what the super-high-end cherries go for but why not look towards adding half a dozen? Even regular cheap cherries would help with the socialization factor if you're not interested in breeding for sale. And who knows, your blood-red might improve the overall genetics enough that they would pay for themselve a generation down the road anyway.