The price of many of these coins could be manipulated so easily. Especially the newer ones like STV. Someone could raise the marketcap of STV higher than DOPE for < 1 BTC. DOPE also could be worth 1000 sat next week.
I don't think price can be used while working together. It has to be a totally different way of working together.
I lean in this direction as well. Can you imagine the protest (and rightfully so) of a much weaker coin leeching value away from one of the more established currencies? That alone would hurt everyone involved.