Hiya, So nice to see a post from you.
I am absolutely the wrong person to offer you an answer. Your question, for me, raises more questions than it answers and they make a book.
Disclaimer...I have not held a class teaching children that age. My past dojo did have such a class but it was taught by other teachers far better suited than I to teach them. I am unsure if children of that tender age even belong in a dojo? I am going to get shot for writing this but it is how I feel and I should be transparent in my answers.
Judo is a full combat activity that by its very nature demands a clear notion of self control and obedience. In all honesty I just cant see a judo dojo ever expecting such notions from children of such tender years, lets face it they have only been out of nappies for two years, have only been able to walk for 3-4 years? Have zero idea of the concept 'no' and 'stop'. PLEASE accept I grossly generalise
BUT with judo I have always found it 100% better to be safe than sorry.
More. In this day and age litigation for injury is a growing field. I am unsure if one could even find insurance for children that age to practice judo, yes I know you wrote "Pre judo" but what insurance company will understand that?
Before I even began to list some of the judo pedagogy I would have to mention further vital points. Teaching minors is a dangerous field today. Accusations can be made and considering judo is a full contact art with ne waza consisting of such waza as yoko shiho gatame, tate shiho gatame, kami shiho gatame....These waza, to an uninitiated parent, may appear odd and questions could be asked. What I am driving at is security in the area of child protection. I tend to turn this concept on its head these days and use the term teacher protection
Teaching or being responsible for toddlers needs very VERY careful consideration and planning. At all times should two female teacher be present on the tatami, as a minimum. I would go much further and insist that one parent or other legally responsible adult MUST be present at every lesson observing said lesson.
The ratio of teachers to pupils would need to be very high.
I am uncertain what one could reasonably teach toddlers that age judo BUT there are young children who have grown into fine judoka so it is certainly possible even if this is the exception rather than the rule.
I cannot and would not even try to teach such a group. I lack the character for this and refuse to be a baby sitter. To me if a pupil is expecting to be taught judo in a judo club that individual should and must understand the basic psychology and understanding of stop and have a decent degree of self control. I am not the person to tolerate a toddler group, I am well aware this is a fault in my character but I cannot teach a group of children that age, I would go crazy in 10 minutes.
So far I have been of zero help to you and am unsure I can improve on that?
Children that age group vary so much in maturity it is impossible to write of a programme that fits all. Groups would need to be formed where the more able are catered for that is why the ratio of teacher pupil would have to be large.
Ne waza is an area that comes to mind. perhaps that would be an area to start. Like I said I don't agree with a dojo becoming a crèche so....again if pupils are on a tatami they are, for me, there to learn judo and not be occupied while wearing a dogi and playing games.
Randori in ne waza may be one area to work? Certainly keep the class to thirty minutes and no longer. Ask your family doctor for a prescription for valium and take at least 5mg before each lesson.
Very best wishes to you and yours my friend,