A big impact on your FPS might have been all the shields that had to be drawn north. Pathing probably wasn't too bad, but there were 50+ units constantly patrolling through 100 other units. "More info" would include things like "were F4/LoS view enabled all game? what widgets do you use?" etc. The infolog posted was not from the game in question, but still contains some info:
[f=0000000] Loaded widget: CameraShake <camera_shake.lua>
Does your camera shake on explosions? I disable this all the time for its super-annoyingness so I don't know for sure, but maybe it eats FPS too?
Does pressing F5 improve your FPS? If yes then GUI has a big impact. If no then it's probably mostly the simulation. After pressing F5, does zooming in on an empty corner improve FPS noticably? If yes then units, weapon effects and similar might have a huge impact. Note that F5 hides FPS display, so you have to either guess (which I only recommend if there is a huge noticeable impact) or find some way to log or still display FPS.