Thanks to everyone for their input. As everyone has said I can see why some were dropped but seeing X-Overd dropping raised a red flag for me as I thought it was doing very well.

As for Sengoku Providence, I can't really say. It's like a cross between FKG and Kamihime and I stopped playing it because it wasn't really friendly towards free-to-play players. But it seems to be doing relatively well as it has a constant stream of events and seems rather active.