I think a big weakness between the major mandriva spinoffs is that there is no interactivity between them, each one seems to be spiraling in its own direction yet I feel if these distros were more aligned things might be better.
I am not saying become the same distro under one roof, they can remain separate distros but its clear where the weaknesses of each disto lays.
Mageia has a huge community yet it seems to have the least amount of packages.
Rosa has a lot of packages but has a tough update process between versions.
Openmandriva has a lot of ambition yet its community is tiny.
You got the recipe to make a great distro here yet the components are not mixed.
I know its a fools dream as once distros splinter off it becomes clear they become hostile towards the others but there is opportunity here