Yeah I’m pretty sure chaos invasions are just realm divide. I’m at turn 107 in a Bretonia campaign where I’m doing badly. I only have 3 full provinces. I ended up going to scandinavia and razing every skaeling and Varg city. It is very slow work.
No peep from chaos so far even thought it’s turn 107. For reference by turn 100 I had killed… 20+ chaos stacks in my dwarf game where I expanded everywhere.