Technically speaking, EAM is designed to be a companion AV. You can install it alongside eset if you want. However, do note that emsisoft is a little heavy on resources, so if you run both, your computer's performance can be significantly hit. If you like emsisoft's behaviour blocker only, you can disable file guard and surf guard as per recommendations of the emsisoft website:
I'm not taking any side. Eset has better detection and responds to new threats very quickly, but has a poorer zero day capability. Emsisoft has a good detection capability that is slightly less powerful than Eset, but it has an excellent behaviour blocker outshines Eset in zeroday protection.