Roy Leclair wrote:
.... do you think that the general Aikido population would stand a chance against a sumo, or even a much bigger person or group?
If Aikido is like most other arts, then for good or ill, up to 90% of the "general Aikido population" are beginners who will quit within a year of starting. If someone has figures to prove me wrong, great, but burnout is a big problem in the arts.
So from that perspective, statistically, the answer would be "no."
As for dealing with a sumo wrestler, why? Do you know one?
Martial artists are rare; some are rarer than others. I wouldn't lose sleep over this one.