Here is what I have from the reference book that I have on hand. Daelyn might have more in what he has, I don't know:
"In 1941, engineers from Mansyu Hikoki Seizo K.K. (Manchurian Aeroplane Manufacturing Co Ltd) were sent to the Tachikawa Dai-Ichi Rikugun Kokusho to develop an advanced version of the aircraft as the Ki-71 Army Experimental Tactical Reconnaissance Plane. Powered by one 1,500 hp Mitsubishi Ha-112-II radial, armed with two wing-mounted 20mm Ho-5 cannon and featuring a retractable undercarriage, three Ki-71 prototypes were built at the Army Arsenal. Despite a more powerful engine and the use of a retractable undercarriage, the Ki-71 had a maximum speed of only 470 km/h (292 mph) and the design was not accepted for production."
So, you are correct. The IJAAS tended to lump recon and CAS into one category (Tactical Reconnaissance). The Ki-71 was just a failed off-shoot of the Ki-51 though. I still favour the Ki-48 myself, though I'm open to other views.
I think that the Ki-71 is a good candidate for the CAS 1944 slot, but take note that it sort of fits into the tactical bomber slot as well. But if we must have a more modern 1944 CAS aircraft, I think that one would be a better choice compared to throwing in an older aircraft that was retired in in 1944.
So then it's up to what aircraft made more of an impact for the 1936 CAS slot, and the 1940 slot. The Ki-30, or Ki-32, and the Ki-48, or Ki-51. More Ki-48s were used than the Ki-51s, but the Ki-51s had their own impact on the war.
For the Ki-30:
"The Ki-30s were first used in combat in
Second Sino-Japanese War from spring 1938. It proved to be reliable in rough field operations, and highly effective while operating with
fighter escort. This success continued in the early stages of the
Pacific War, and the Ki-30s participated extensively in operations in the
Philippines. However, once unescorted Ki-30s met
Allied fighters, losses mounted rapidly and the type was soon withdrawn to second-line duties. By the end of 1942, most Ki-30s were relegated to a
training role. Many aircraft were expended in
kamikaze attacks towards the end of the war.
[5]
From late 1940, the Ki-30 was in service with the
Royal Thai Air Force, and saw combat in January 1941 against the
French in
French Indochina in the
French-Thai War. Additional Ki-30s were transferred from Japan in 1942."
https://en.wikipedia.org/wiki/Mitsubishi_Ki-30#Operational_history
For the Ki-32:
"Ki-32s during
World War II were also supplied to the
Manchukuo Air Force to replace their obsolescent
Kawasaki Type 88/KDA-2 light bombers; they were the main bomber of that service through the conflict.
[4]
After their withdrawal from front-line service in 1942 the Ki-32s were used in a training role."
https://en.wikipedia.org/wiki/Kawasaki_Ki-32#Operational_history
For the Ki-51:
"The
Mitsubishi Ki-51 (Army designation "
Type 99 Assault Plane".
Allied nickname "
Sonia") was a
light bomber/
dive bomber in service with the
Imperial Japanese Army during
World War II. It first flew in mid-1939. Initially deployed against Chinese forces, it proved to be too slow to hold up against the
fighter aircraft of the other
Allied powers. However, it performed a useful
ground-attack role in the
China-Burma-India theater, notably from airfields too rough for many other aircraft. As the war drew to a close, they began to be used in
kamikaze attacks. Total production was around 2,385 units.
On the day
Hiroshima was destroyed by an atomic bomb, two Ki-51s scored the last Japanese sinking of a US warship, sinking
USS Bullhead (SS-332) with all hands.
Charles Lindbergh, flying a
P-38 Lightning shot down a Ki-51 after a vigorous dogfight in which the much slower Ki-51 utilized its low speed maneuverability and made a fight of it."
https://en.wikipedia.org/wiki/Mitsubishi_Ki-51
For the Ki-48:
"The aircraft served in
China from late 1940, replacing the
Kawasaki Ki-32, and were widely used in the
Philippines,
Malaya,
Burma,
New Guinea, the
Solomon Islands and the
Dutch East Indies, where the Ki-48 Ia and Ib models, slow and badly armed, were supplemented by the marginally improved Ki-48 IIa and IIc, which were maintained in service along with the older types until the end of the war.
All models continued in service until the
Battle of Okinawa during April 1945, when many were converted into
kamikaze aircraft (Ki-48-II KAI
Tai-Atari) armed with an 800 kg (1,760 lb) bomb."
https://en.wikipedia.org/wiki/Kawasaki_Ki-48#Operational_history
I'd make the CAS for 1936 either the Ki-30 or 32, and 1940 the Ki-48 or Ki-51 since actually the Ki-51 came out six months earlier than the Ki-48 but both are candidates for the 1940 CAS slot Finally for 1944 CAS, I'd go with the Ki-71.
To me it all comes down to the 1936 and 1940 CAS slots. It's a weird one where the Ki-30, Ki-32, Ki-48, and Ki-51 all came out from 1937-1940. Maybe choose one from the first two, for 1936, and one from the second two for 1940. There is no way to include everything. Until we actually get factories owned by certain companies that produce their own aircraft or have license to produce someone other companies aircraft, then this cannot every be 100% accurately resolved.
