Number 1 - Perhaps 'certainly' was a bad word choice, but I meant it in a light, 'the chances are quite high' way rather than a FOR SURE way.

Number 2 - With 30 years, you would know the ins and outs and what to look for that enable you to house multiple snakes together. A newbie would not know these things. It is SAFEST for any new snake owner to keep their snakes separate, since things COULD happen that they would want to avoid...such as dominance behavior and fighting.

Number 3 - Just because it works for you does NOT make it universal for everyone else. Nor does it make other practices 'wrong'. Just because you have not had issues with fights or dominating behaviors in your corns does not mean that it hasn't happened before for others. Have you ever heard "An ounce of prevention is worth a pound of cure"??

Number 4 - I do not have PERSONAL stories, but I do have second person knowledge seen first hand. A friend of mine had a 55 gallon tank with 3 corn snakes of different sizes/ages. No matter what I said, she ignored my ADVICE that she separate them. Then she started having regurge problems and, since she couldn't figure out which one was doing it, she just kept feeding them the same way and it continued. Eventually, of course, she learned that it was the smallest corn since it started looking VERY thin and sickly. By then it was too late and that snake died not long after being discovered..even after she put it into its own enclosure.
I had to watch this going on, and she never once listened to my suggestions on husbandry. Even after she lost that one, she just said the little one must not have been 'strong enough' and continues keeping the other two (who are also of different sizes) together in that tank.