Regarding the fact that the So-ki used Type 98 (1938) 20mm guns and not Type 2 guns, check the Wikipedia page hat clearlt states that it used Type 2 cannons.
However the Wikipedia pages doesn't refers it not as "So-ki". Moreover, there seems to be a paradox in the Wikipedia page: it refers as the title "Type 98" and then "Type 2 mounted" in the content.
Then if you check a link it states, it show a modified Ta-Se with twi Type 20 mm guns which looks A LOT like the So-Ki! (need confirmation).
Is a modified "Ta-Se" or the actual So-ki?
(Ta-Se was short for "anti-aircraft tank" and had a single Type 98 20 mm and used a Type 97 (1937) Te-Ke chassis, So-Ki was short for Sokosha which stood for armored vehicle/car and utilised dual Type 98 20 mm and used a Type 98 (1938) Ke-Ni chassis, however to make this vehicle more potent, upgraded Type 2 20 mm cannons (nicknamed Soki) were developed specifically for the So-Ki (according to Sensha's website, just need to find out his references!)
I will keep doing historical research regarding the So-Ki, as I find this very interesting.
- From the information available from Wikipedia and the other sites gathered in a quick search, I believe the So-Ki was initially developed with the Type 98 20 mm cannons, however, as it evolved over the next couple of years during development the Type 98 cannons were switched out with the Type 2 (1942) 20 mm cannons which were lighter and had a higher muzzle velocity. It is possible that the final production version (if it had gotten that far) would have been the So-Ki with dual Type 2 20 mm cannons, however, documentation needs to be found to prove/disprove the facts (who knows where the person who typed up the Wikipedia article got their facts from). From what I have been told, right now Sensha's blog post is probably the most accurate information out of all you found so far, apparently, he did quite a bit of research in helping Gaijin develope the Japanese tank line when it was added to the game. It might be worth trying to reach out to him to see if he could provide references (or even .pdf copies if available) or possibly find the resources he used. You have just become a detective, look for clues, build your case and with documented facts, the War Thunder wiki may have the most accurate information about the So-Ki thanks to you! - AN_TRN_26 (talk) 16:55, 1 May 2019 (UTC)