General observation.
Bish tend to have the numbers more often than not, and are probably the best at consistently posting large missions.
Rooks fall in second on having numbers and running missions. Very often I've seen Rooks concentrate more on lower numbered Knits when Bish had the number superiority in an arena.
Knits usually have lowest number in the more crowded LW arena. They sometimes have the numbers in the lower populated LW arena, and apparently have some success at peak times in European or Asian time zones from what I gather on some maps. I see the least amount of coordination and cooperation and missions while flying Knit. I also see the Knits getting rolled most often.
Last night, Mountain Standard Time, in Orange on the new map was pretty typical of what I've been seeing in the most populated LW war arena. There have been exceptions, but, generally.....
Either the Rooks or Bish will have the greatest numbers. The Knits generally have the least numbers in the populated LW arena. Sometimes they have the numbers in the lower populated LW arena.
The Rooks or Bish will be doing well at posting large missions. The Knits are probably the worst at it lately, as well as any kind of coordination outside of a very few squad efforts, most of which look like defense and fighter sweeps.
The Rooks AND the Bish will have a large percentage of their players going after the outnumbered Knits. At one point I saw 4 Rook, 3 Bish, and 12 Knit flashing bases, and Knits were getting rolled up in the north (The Rooks in the West had the numbers, the Bish had similar numbers to the Knits, and it was the Bish rolling up the Knits in coordinated attacks --- most Knits involved in a furball all night).
The Bish and Rooks tend to finally turn on each other after Knits rolled back to their uncapturable bases.
NOW, I don't have any chess piece loyalty. My first 1-1/2 years I flew Rook, but now I log in, I tend to switch to the country with the least number of players. Just happens to be Knit most of the time these days. If things are especially "squeakish" there and becoming frustrating (it happens sometimes), then I move to the second most populated country. I avoid being part of whichever horde is operating in an arena.
Now, other times of the day for different time zones, I cannot say how things break down. And these trends tend to change over time. I suspect the influx of "squeakers" over summer and the lower participation of some of the "old timers" during "squeaker season" has something to do with this..... possibly there have even been a loss of many of the older players, from some of what I've seen posted in the game, but only HTC knows whats going on with their subscribers.