- are being actively maintained, i.e. work on the latest patch
- are of at least passable quality
- not massively opinionated (e.g. Poland STRONK, anime Japan etc.)
- don't require a particular set of DLC
Honestly the same critic can be made about the official trees:
-most of the trees one released have few variations despite changes in game mechanics;
-quality varies a lot from tree to tree as discussions in the forum proves and creative wise I wouldn't say adding ideology paths for the sake of it is a good quality;
- That some paths are a meme is now a meme on itself ;
- And finally all official trees require a DLC to work.
Take BtB for instance adding focus trees for Greece, Bulgaria and Turkey. Of the three nations, there is no a single major nation and one of then didn't partake into WW2 into an active manner (although being the most played of the three). All the trees feature content of dubious quality from what I read, and the DLC itself was make by a third party.
With all that said, it's obvious that if you don't intend to play this nations, you should not buy it. However, what about official expansions coming with major mechanics reworks. Why should the consumer pay a premium for a content of dubious quality? If for Barbarossa I do not intend to play alt history paths for Italy and USSR nor the additional focuses for minor nations but I'm interested on the mechanic it introduced, why should I need to pay an extra for those focus trees?