Soviet Union was a major nation in 1930s. They were also making monoplanes, both fighters and bombers. Spec difference in 1934 was, in mph, 271 (I-16 with 640 HP Cyclone) - 230 (Gauntlet with 645 HP Mercury) = 41 mph.
The minor nation of USA in 1934 have had 275 mph P-30 fighter in service...