Playing as southern whites, I got option about Yudenitch army. Option didnt had any description just picture. I took that option but didnt get any notifications or anything next turn. After some time already at the beginning of 1920, I noticed that pskov had some units inside. After looking at them, they had same officers as force that I already got from north west army formation event. So now I have a pair of all north west generals.
Attached save after I spotted that.