That's we're we don't agree. Junkers could have started building the Ki20 at once. They had built the G38 (two) and assisted the IJA in building the Ki20. They could build a limited series at once, while expanding facilities for later Ju89 production. We are talking small numbers, of course, lets say the Lufthansa orders four G38 for 1934 that turn up as Ki20 followed by 12 per year up to the point were the Ju89 is the natural candidate to replace it. That gives 40 aircraft to be used as a threat at Munich followed by a larger number of Ju89s.
For the sort of numbers that we're talking about they would have been hand made, rather than machine produced as one would for serial production.
That's enormously expensive per unit and in the 1933-36 period every Mark is needed for the expansion of the aircraft production industry and various make-work programs to get Germany to full employment to bolster Hitler's political position. So the LW did not have the funding to spend on such an aircraft before 1936, which was the year the Do-19 and Ju-89 entered prototype production.
I highly recommend reading Edward Homze's 'Arming the Luftwaffe', Hooton's 'Phoenix Triumphant', and James Corum's 'Creating the Operational Air War' to get an idea of the contraints the LW was under during the 1933-36 period when it came to producing a military bomber. While technically possible for Germany to produce the Ki-20, it would have been enormously costly at a time that both Germany and the LW could ill afford it; when they prepared their industry militarily, they were more focused on getting their air men trained on medium bombers before jumping to the next generation of strategic bombers, the Ural Bomber project.
Even if they mass produced them, which would be enormously costly at a period where Germany had little experience with military aircraft either with their military pilots, ground crews, or in the majority of their aviation industry, they would have fewer overall aircraft. At the time more aircraft was viewed as more threatening as part of the 'Risiko Luftwaffe' doctrine. 400 Ju86s and Ju52s was more threatening than 40 Ri-20s in 1935.
Also remember that politically Germany was still under the threat of the West invading the Rheinland if Germany was caught violating the terms of Versailles by producing such a bomber; at least the others could be disguised as civilian aircraft, which they essentially were. The Ki-20 was a known military aircraft and Hitler was still more concerned about consolidating power than building up the LW, while the LW, which didn't exist officially until 1935, was more concerned with putting together a staff. There wasn't even a real staff hidden in the RLM until 1933, as Hitler dismissed the former clandestine head of the LW, Helmuth Wilberg, for being half-Jewish. Wever came in at the end of 1933 to replace him and needed time to figure out what he was doing before he could seriously start ordering anything to be built.
Similarly Erhard Milch was brought into the RLM when the ministry formed in April 1933, which took time to get organized before they could even exert control over the aviation industry:
https://en.wikipedia.org/wiki/Reichsluftfahrtministerium
Beyond that Germany needed to build military airfields, of which there were virtually none in 1933, so they had no place for military aircraft even if they had any. Prior to 1934 there was no way that any authority or even means existed to order military aircraft to be built, thanks to the sidelining of Wilberg, promoting of Wever, splitting of the Reichswehr, creation of the RLM, expansion of the aviation industry into the military realm, and building up of the infrastructure in Germany of an air force from the very basic levels. Basically it was impossible for a coordinated policy to exist to produce the Ki-20 in 1933.
By 1934 the LW ordered the Ural Bomber project. So they decided that they needed to develop the technology domestically at the industrial level first, while they focused on getting the LW, as much as it yet existed, familiarized with militarized civilian aircraft that lacked even bomb bays. These were two engine aircraft, which were still as yet beyond the experience of all but a handful of men that had been to the USSR at the Lipetsk air station. So the LW was busy using its limited funds building airfields, expanding industry, training ground crew and airmen, setting up training establishments, and in general trying to recruit and train officers and every other rank, as there had been very little preparation by the Reichswehr for the LW to even exist. It seems that Wever waited for the Ural Bombers, rather than jumping in with the Ki-20, because he needed time to get his service ready to even be able to handle such an aircraft; at this point only civilian pilots even knew how to handle a four engine aircraft and they were all on duty training combat pilots how to handle two engine aircraft. By the time the LW was ready to handle the technology of the four engine bomber, the Ural Bombers would have been ready to set up a training establishment for a four engine aircraft. However of course Wever's plan went out the window with his death in 1936 and his successors and Goering killed it with very little forethought. Of course by then there was experience with the FW200 and Geschwader 200, so the He-177 would have been an aircraft with a waiting training establishment, but of course the technology was bungled by Udet and his technical team.
So it seems that the LW was in no position to handle such an aircraft as the Ki-20 until it would have been supplanted by the Ural Bombers, which meant there was no point in bothering with ever even making it.
The POD you're looking for is Wever living past 1936 and sticking to his strategic bomber plan. The Ki-20 is unfortunately an aircraft without a place in the LW.