Seriously this: smoke stacks are a carefully engineered structure specially to ensure air emissions diffuse and don't roll along the ground.
https://www.youtube.com/watch?v=RnYdt4T76mk
You absolutely cannot park a bunch of truck mounted generators next to an existing plant and go "yeah it won't make a difference".
Once, when I was a child, I remember the carefully engineered smoke stacks in Sudbury Ontario spilling out acrid smoke sideways, and then straight down into the town.
Back then, Sudbury looked like Mars.