Very thorough postA suite with more features, ESET, Kaspersky, probably also Malwarebytes...
Something relying on VirusTotal, https://play.google.com/store/apps/details?id=com.funnycat.virustotal
Something relying on a models based on MachineLearning, https://play.google.com/store/apps/details?id=com.intelliav
Currently I do this way:
I am testing Zemana AntiMalware for Android, so I mainly use that for realtime protection; it doesn't have any unnecessary jiggles, and I appreciate the new introduced cloud-scan, as a second opinion, I use IntelliAV; monthly or so I launch the funnycat app to get a comprehensive report of the apps I have.
-A little OT-
And these more or less my security view for strictly AV suites for Android, I think the less, the best; Android security model is many time broken by users choices, root, xposed framework, permissions...
I audit every app dns traffic through PiHole, and if I have a doubt about one app, I ask services like NVISO ApkScan - Scan Android applications for malware for a static analysis.
During the last year, I replaced almost 70% of the apps I was using, with OpenSource FDroid alternatives; lately, for every app I do the following:
A little inspection through this app: apps_Packages Info | F-Droid - Free and Open Source Android App Repository
and I check against ClassyShark3xodus | F-Droid - Free and Open Source Android App Repository this for known trackers, in alternative also Exodus Privacy is quite ok...
Most Android antiviruses (including the Xiaomi's security app), just scan apps when you install or update them. For example, apps don't get scanned when you open them.I have a Huawei, with Avast build-in protection, but i think it's not real time,you can only scan on demand to see if you are infected.So consider this,if it is the same in Xiaomi maybe you are not protected.
In my case, Avast(built in) doesn't scan them at all, at install or in update.It's working only on demand, scanning files, doing just a static scan.I have Bitdefender, paid edition,to have real time protection,working on downloading apps,update them and as a web protection in browser.Most Android antiviruses (including the Xiaomi's security app), just scan apps when you install or update them. For example, apps don't get scanned when you open them.
In my case,i mentioned above,Huawei built in with Avast is only for static scan and not real time protection.The only reason to add an Antivirus to Android phones with built-in security is for functions your phone doesn't offer such as anti-theft or password blocking specific apps.
Otherwise built-in is more than enough.