Yes! Emsisoft Anti-Malware is technically an antivirus, so it disables Defender like all other antiviruses to avoid comflict. Says Emsisoft:"Our lab has determined that classic viruses only make up less than 0.5% of total threats (in 2016). Using "Antivirus" would therefore be wrong by definition. We're perfectionists so we have elected to use the broader term "Malware" as it stands for all kinds of online threats."
I'm very happy with Emsisoft AM. At first I was having performance problem. Disabled memory usage optimization and it was fixed.
I have Malwarebytes 3 premium too but it slowed down my computer so i keep it disabled and use as an on demand scanner once in a while. Hopefully, they make it great again someday.