Yes, I think you are right on it, as usual. And we are getting closer to nailing the puzzle of 34 chronology and where it sits amongst its predecessors and competitors. I don't think its a coincidence that Diana arrived at those dimensions for its 45 and 34 models. Its common practice for manufacturers to buy examples of their competitors wares , especially class leading ones, and tear them apart to see what makes them tick. Doubtless, they thought 28x77 was a great combination, also.
The 45 was a big departure from the 35 and the 34 was very different again but there has been no significant developments until they put a gas ram powerplant into a 30 year old design. And now the 34EMS. I am interested to find out how that one performs.