Why don't marksists and national socialists just fight each other?

I mean, communists and nazis are natural enemies, in that communists believe in the destruction of the state, while nazis believe in the expansion of the state in order to resurrect a great Germany. Both ideologies are antagonistic, as one seeks to destroy the state and the other seeks to expand it. Communists even see the state as inherently oppressive, therefore, nazis would be the oppressors and communists the liberators. Instead of fighting these dumb right wingers, they should each other.