So if project A can handpick improvements from project B.
But project A creates 10x as many new improvements on its own.
And it has 10x as many contributors to its own project.
And project B is not allowed to merge back improvements (license-wise).
It simply means project A is going to win out in the long-run as long as the project stays as healthy as it is, no matter how healthy project B is. What project B can do in this case is make sufficient changes to the code-base so that improvements can not be easily merged into project A. Or make so many changes that project A runs out of resources to merge everything back into project A.
In this case specifically, it seems that AOO has the mindshare of the users and LO has the mindshare of the developers. It's more likely that a contributor knows what the difference is and where to contribute to. If ohloh.net does make something clear it is the divide between developers and users.
PS The 10x as many is taken for the sake of the argument, whether it is indeed 10x or 5x is irrelevant given enough time.