No, I do get that, but the emissions from extensive fires across the region are still substantially different from what you'd see in the kind of event we have seen produce actual global cooling events like the 1815 eruption.
I'm willing to believe that it's possible, but I think the initial study suggesting it could happen makes some overly broad assumptions and I've seen subsequent studies fail to reach the same conclusion with similar analysis.
For all people like to compare it to WWI, they don't ever seem to think that it's probably going to end like it where one side eventually has its ability to maintain the front destroyed and then starts losing massive amounts of territory very quickly.
At the rate the western front was going it would have taken hundreds of years to get all of Germany, but that's not how wars of attrition work.