Yep, there's the occasional knit/rook fighting in morning/early afternoon because it's more fun than going up against the swarm. This is the remnant of when knits had been hitting rooks while rooks were probably defending vs the bish locusts- knits took advantage of the lack of rook defenses (rooks do the same to knits sometimes.) As the evening progressed, knits went for bish and I believe the map was reset overknight. <-- see what I did there?
There is usually some knit/rook fighting - just sometimes with larger numbers than other times.
Towards afternoon and evenings, once knit/rook have taken back their primary bases, they often just keep going since, hey you need 20% of bish bases, so we may as well keep going and deal with the other side (knit/rook) later after we get a margin of comfort. It's this time when you'll see heavier knit/rook action while bish are left in recovery mode (with fewer players.)
This often sets up a map reset by the wee hours overknight (heh) players. (You should see capera's rants on the subject in those wee hrs.)
Reset or not, once the morning locusts log in, they set the tone for the rest of the day.
A side observation: it's not too often at any time of the day where you see action being spread out equally on all three fronts. It's usually two sides heavy on one with some minor, or zero, action between them. I think this is more reflective of lower overall numbers and human behavior than a deliberate choice - people like flying around other people. But sometimes you have to take a step back to see the bigger picture.
Personally, I typically avoid flying either with or against a large group when there's minimal response.
Here's a screenie at 12:20pm cst showing the dropoff in locusts and a relatively quiet time until around 3pm cst when more start logging on. The action is relatively spread between the three fronts, but it's mostly singles doing strat runs or pestering some town/base - nothing coordinated and nothing that will indicate a fun fight can be found in this whack-a-mole deadzone.
In that picture there is a group of us taking rook bases.