Yes, it is frustrating that Knights get rolled over so much, even if you're generally a furballer like me and only care a moderate amount about the greater war. I've looked at this very issue within the last month. The numbers issue is variable throughout a given day. The Knights do not have substantially different fluctuations wrt numerical odds than the other countries. I will say that of the three countries, there could be slightly more willingness to gang Knights since A. they prefer furballs and furballs don't go with hording B. They are less likely to take back what is taken. However this is always countered in the end since any country seeking to win the war must hit both its opponents.
The biggest issue for Knights is lack of coordination which really comes from a lack of will for coordination. When I looked at this last month I noticed that 8 of the top 13 fighter scores at that time were held by Knight players along with 22 of the top 50 overall. (Haven't checked this month) There was a similar trend in attack (don't remember the specific #s though). However when it came to bombing, Knights represented about 1/3 of the top. My take is that the Knights prefer the furball to the war and they're disproportionally good at it. In fact, some players realize that the war often times counters personal goals. (Kill the dar or drop my ord here and kill those low bombers?)
I like winning, I like coordination. From a philosophical perspective I am very much Rook, but my squad is knight and doggone it, it's fun. You have to be on for 2-3 hours to see any significant swing in the war and many of us simply don't have the chunk of time required to glean that satisfaction.