It need not be unlikely. Once you become an acknowledged expert, other people may collaborate with you in parallel. You contribute some of the main ideas, and y

It need not be unlikely. Once you become an acknowledged expert, other people may collaborate with you in parallel. You contribute some of the main ideas, and your co-authors will flesh out and write the paper. I do not see anything wrong in this. Currently, Erdos and Shelah are in the 1100-1300 range. Euler published around 400 pages (or papers? I am not sure) posthumously!