There is a big difference between 5 am gmt (which are indeed the dead hours), and the few hours before and after towers open which do have quiet alot of people playing. I am not saying they have to be open the full 24 hours but having em all synced in the same few hours give or take 1/2-1h is the complete opposite thing.
I too notice the numbers slowly declining over the past period, having every single field synced in the same few hours is one of the (many) reasons this is happening. I have orgmates who get home from work and find out that all fields just closed and that starts to get frustrating after a while for people who like tl 7 wars. Causing a few of them to actually stop playing or logging on less and less.