The horseshoe theory is bullshit to discredit anti establishement leftists.
The idea of radical leftism is that the capitalist system needs and breeds inequality and the state is its assistant. There is no overlap of fascism and leftism. There is a lot of overlap between fascism and capitalism though.
Dont believe stuff like this. It has been disproven many times.
Radical leftism means in essence:
- everyone is the same
- everyone deserves the same satisfaction of their needs
- a roof over your head, food and drink are inalienable rights
The only thing i would warn of is that just because someone says they are leftist, socialist, communist, anarchist, etc doesnt mean they really are. Examples: national socialists and anarcho capitalists. They're both just using the term and perverting the idea. Then there are radical leftist parties that are lost (like russia apologists).
Of course you need to make an informed decision but yes, radical left all the way.