Another, earlier, Finnish fighter is more instructive. VL Myrsky
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Now the project started in May 1939 (?) with the initial requirements, first flight took place Dec 23rd 1941 and first units got production aircraft in 1944. Which is actually not too bad.
It also allowed some later innovations to be used. Like cowling and exhaust thrust ideas that were not in existence in 1940-41. This did allow for better performance than was allowed by 1939-41 production fighters using similar engines. Yes it used wooden construction as noted earlier and it had problems with bad glue.
More subtle problems were the 300 liter fuel capacity and the rather restricted ammo capacity one source says 220rpg for the inner guns and 260rpg for the outer guns. This may have suited conditions in Finland but perhaps not in some other areas?