Having read the interview with Mongolian sumotori Dolgormaa, I'd like to tell a story related to the subject. Based on my own experience, I got certain that a female novice could successfully wrestle in the Sumo style as long as she has enough weight and dexterity. My wife is a good example. Everyone in our family likes wrestling: my sons (12 and 10) and even my wife (we love wrestling with each other for fun). I achieved the master of sport title in Judo and Sambo; currently, I am a Judo trainer. Recently I learned Sumo (which I hadn't been familiar before) and even trained a lady in Sumo.
My wife Marina has been enthusiastic in sports since her childhood - she practiced volleyball and basketball. After she gave birth to our two boys, she noticeably put on the weight, particularly in hips and legs. However, she is still agile and deft - she is very far from an appearance of awkward fat ladies, even though she looks quite stout.
People training in our luxurious athletic gym are not ordinary - the most of them are tough businessmen and their wives who like eccentricity and zealously keep their figure. We have a Judo class, in which a few women of various age trained. They are usually quite slim but one day, a very big young woman came to us asking for being trained in Sumo. She had practiced Judo and after her fortunate marriage a reach guy, she got fat. She heard that Sumo was the best sport for big girls. I was not familiar with Sumo that time, so I asked a friend of mine, Alexander (who knew the sport and was not too busy at that time) to come to us for training her. The woman's name was Lena, she looked very impressive: being as high as 6', she was heavier than I was (even though I am a big guy) - she weighed 230lbs. Since there were no more sumotori in our gym, Alex was the only her sparring partner. Judo skills helped Lena to practice Sumo, especially the well-developed balance instinct. I was glad to get familiar with the new sport, so I interestedly watched their training. Once Alex gave me a few Sumo lessons, I became a "sumotori" too (thanks to my Sambo and Judo experience).
After a while, Lena became bored of training with the same person. She asked for a female sparring partner but we did not have any sumotori in our groups, neither we had women even close to her by weight (men either though). Alex was also tired of visiting us just for her sake and after all, he handed her out to me assuming I was enough familiar with Sumo to train her independently. When I first came out to work with her in sparring, I just recalled our fun-wrestling with my wife and involuntarily compared the two big girls. Strangely enough, but the comparison was not in Lena's favor in spite of her substantial weight advantage over Marina.
One day, Marina came to the gym to pick me up for a concert. At that moment I was just working with Lena - about fifteen minutes of the session remains on the schedule. While waiting for me in the lobby, Marina was watching Lena through the window to the training room with unconcealed interest. Her interest probably reflected a kind of jealousy - isn't it easy to see a husband being in the close physical contact with another woman? After we left the gym and got into the car, Marina said that she would easily pin the fat gal, even though she yield to her at least 65 Lbs. I just recalled that had a similar feeling when first sparred with Lena. Why don't we really try, I thought. It would be good for Marina who had given up sports and plumped up. Besides, I was very curious to watch these two competing. So, I told my wife that I would be happy to train her and to teach her Sumo basics. And if she liked it, she would practice with Lena. Marina always liked adventures, so she was quickly convinced.
I took Marina to the gym and taught her Sumo and Judo basics for a few weeks (keeping that in secret from Lena). Then I announced to Lena that I found a right Sumo partner for her (not mentioning at the beginning she was my wife). Lena was very happy but when I introduced Marina, she was unable to hide her disappointment looking at a pear-shaped plump girl who was much smaller than she. But I just took them into "dohyo" and required them to compete three times following the Sumo rules. Lena arrogantly looked down at her "weak" opponent but after the signal, Marina pushed her out of the circle just in a couple of seconds. After that, Lena revived and the second round was more interesting - for about ten seconds the girls trampled in attempts to push each other out until Marina managed to drop her giant opponent utilized her big hip as leverage. Then Lena toppled Marina in the third round just bringing her whole weight on my poor wife.
These two thirty five year old women had very different constitutions - Lena had a big upper body and relatively narrow hips, while Marina had quite feminine torso and powerful massive hips. Lena's arms and shoulders were very strong, whereas Marina's strength concentrated in her lower body. Perhaps, on the ground, Marina would not have any good chances against Lena but Sumo is a standing combat in which she had the advantage due to her outstanding ability to keep balance (caused not just by her low focal point but also by her good volleyball and basketball skills). I always admired her capability to keep balance against an experienced male wrestle (I mean our fun-wrestling with her).
In fact, willing to be the first in the competition between the two women stimulated their training efforts. They even got rid of some extra fat. I would not say they became bosom friends (a rivalry is not a good stimulus for friendship between women) but they deeply attached to each other and were literally unable to exist without each other. Sometimes we took Lena and her husband for vacationing and all hell was let loose when our wives frolicked - it must be seen! However, after a short while, Lena happened to have a car accident and damaged her arm, leg and a few ribs, so she had to stop practicing Sumo. So did Marina.
Marina fell in love with Sumo wrestling, so when we are resting outdoor, she likes to challenge our male friends to wrestle with her in a circle (women are not even offered). Believe or not, she defeats about 50% of men.
I have told this story in order to support the opinion that Sumo is the best combative activity for women, in which beginners and amateurs can learn it quite easily. In this sport, a plump (but lively) woman can successfully prove herself.