Short answer: Mannerheim.

Longer answer:

Finnish civil war is actually one of those bits of history that's still not completely openly discussed and analysed because the rift it struck between the Whites and the Reds was extremely divisive and traumatic. There are still quite a lot of dirty laundry that hasn't been cleaned and aired out because of it. It's not totally unheard of to witness someone whose family was on the side of the Reds to call someone coming from a family of Whites as a "butcher" ("lahtari"). Summary mass executions and internment camps are not a preferable topic of conversation no matter what company you're in. This means that a lot of the strategic troop movements and decisive battles are not necessarily that much in common knowledge.

Still, one of the few major differences between the Great Communist Revolution in Russia and the Civil War in Finland is in fact C.G.E. Mannerheim, being a trained and highly accomplished officer of the Russian Imperial Court, his strategic skills were integral in securing the victory for the Whites during the Civil War, and in successfully defending Finland's independence against Soviet Union during the Winter War and also in the Continuation War.

As for the motivations of the people, the communists in Russia revolted against the oppression of the nobles and the Czar. As a strategic error on Lenin's part he had already granted Finland it's independence as the bolsheviks had already deposed Nikolai II. Finland had thus gained their independence, from a position of being already an autonomous State. The grievances any Finns had with the Czar and Russian nobility were thus settled, so the question in the Civil War became as not only extending the international socialist revolution as Lenin wanted within the borders of Finland, but also whether Finland should be annexed again as part of Russia.

The Revolution in Russia also meant that any Russian troops within Finland weren't necessarily motivated enough to fight for the Reds in Finland, and the whole military structure in Russia was not as capable of training the Finnish Reds. The Whites on the other hand, had already troops who had gotten Jäger training in Germany and Germany assisted the Whites with supplies and a relatively small number of troops.

edit: corrected the part on Winter War and Continuation War