Comrade Cowbee already listed the issues with Vaush that I'll not repeat here.

That being said, I can't really say much about Vaush's ideological stance since I don't watch him. What I can say is that I doubt he's anywhere close to Hasan ideologically if going by how his fans act. Most of the times what I have seen is a pretty clear anticommunist stance from them that I cannot comprehend, specially when they love to laud Vaush as such a great leftist youtuber.

Unless you have have disagreements with Hasan

I do have some issues with Hasan actually, which I'll use this comment to inform anyone that reads it after my recommendation. I don't watch a lot of Hasan, I usually see bits and pieces of him here and there when youtube recommends him to me, and I mostly disagree with some of his instances on China, from the little I seen he's mostly pro China, but I have seen some iffy stuff on his knowledge about the Uyghurs. I also don't think his format of reaction/commentary to be that great either, specially since he likes to leave mid video a lot while it is still playing for his audience. I think his content could benefit a lot more if he actually paused on key points of the videos he reacts to to explain, debunk and or give context to the stuff said while also giving his opinion and stance on that as a Marxist. If you want an example of what that would be like, the brasilian youtuber João Carvalho I mentioned before does this, a lot, like to the point of even being a bit tiring sometimes, lol, but makes the content usually pretty transformative instead of just content theft.

That being said, Hasan is a very important figure in radicalizing and propagandizing for the left in the english speaking internet since he's at the top of the left pipeline on youtube at least. I recommend this video by Yugopnik to learn more about this.