I'm seeing it depends on the track. AI set up for passes at Zhuhai, Hockenheim, all the Nurb road courses, Leguna Seca, Long Beach, Monza, Oulton Park, Donington, Bathurst, Road America, Texas and Daytona Road Course. Mind you, this using TCR cars AI @100/100.
Tracks where I've seen processions are: Snetterton, Oschesleben, Algarve, Sugo(there were very few passes made AI-on-AI, but I did fight with 3 AI back and forth for last place), Monaco, Ruan...Ruin..Rune de Estate or whatever its called, Fuji is hit or miss.
Trust, I've been hitting this game hard since the patch. Having the week off and playing as much as possible(it's 12:42am). Ai have been tough. I've only won a handful of races(clean racing) and scored a few podiums after all this play(also due to some multi-class races and different disciplines).