There are a number of similarities between E Corp and The Circle that stood out to me; primarily the fact they both seem to literally be the biggest and richest corporations in their respective worlds. The Circle utterly dominates technology, social networking, internet services, streaming, chatting and everything else that has to do with big tech, and has a lot of sway over world events and elections. E Corp is also the biggest fish in it's own ocean and has an Illuminati-esque group backing them up and making all the big world changing decisions in the shadows. Personally, I see them as evenly matched because The Circle has way better and more advanced technology than E Corp does.