Re: 1939 Soviet invasion of Finland (Winter War)
Just a footnote, Yugoslavs toppled the government that joined the Tripartite Pact as soon as the agreement was signed and thus it was never implemented (also, they only signed it after a direct ultimatum from Germany, and after all of their neighbours, apart from Greece that was also being invaded by the Axis, had already joined). This prompted Germany to postpone the invasion of the USSR, so that it could destroy Yugoslavia first. This meant that Germany, together with all the countries neighbouring Yugoslavia (apart from, again, Greece) attacked simultaneously. Parts of the country were annexed by Germany, Italy, Hungary, Bulgaria and Albania (Romania refused to take any Yugoslav territory). In most of what remained, the fascist Independent State of Croatia was formed and in central Serbia a puppet regime was set up.
So let's not go too far when trying to downplay the Finnish involvement in the Nazi war effort.
P.S. Also regarding Bulgaria, they too only joined the Tripartite Pact in 1941, and only after a direct ultimatum from Germany, although they were quite happy to take advantage of the alliance to satisfy their irredentist ambitions against Yugoslavia and Greece. So, whatever any of them did or did not sign, Bulgaria and Finland spent about the same time fighting along side with Germany in WWII.