Sure, they are hard but not very hard. I found that shooting at them, storming to the opposite end of them and jump above them using downward slash helped a lot. I don't remember which charms I had equipped, though.
I think I was done with them within 45 minutes. There were other bosses that I spent twice the time on.
Also, I learned this afterwards, there is a secret room above them that lets you drop a chandelier on one of them, taking it out.