Sixty years ago RD Lawrence (an eminent British diabetologist) described 3 types of diabetes, the first was classic 'juvenile diabetes' as it was called then. The second he associated with obesity and overfeeding,the third he categorised by describing a patient who had absolutely no fat, yet was extremely insulin resistant so needed between 1600 and 2000 units of insulin a day, without that she developed ketosis and lost even more fat.
SInce then knowledge has grown, we know that there are thin people with insulin resistance and obese people with insulin resistance (and every body type in between) . We know that there are people with autoimmune antibodies who experience beta cell destruction, hence type 1 diabetes yet people with the same antibodies without diabetes. There are also people with no evidence of autoimmune antibodies who develop insulin deficiency.
Yet we still put people into a limited number of boxes.
I have a variety of T1, developed at an older age, I don't think it is exactly similar to the type developed as a child.(for one thing I had a mature metabolic system long before I acquired it) and I know it seems somewhat easier to control.
The more I read. the more I think that there are a considerable number of varieties of diabetes, certainly more than 2 main (plus the others caused by specific genes or damage to the pancreas already recognised) We share a common symptom of hyperglycemia but the causes and best treatments are varied.
On some diabetes forums there is the acronym ydmv (your diabetes may vary).