Well, almost!
2 AVs cannot and should not be run together, or even installed on the same computer at the same time, even if one of them is disabled and the other one is running.
They are like alpha-males in nature, think of how 2 male lions rarely will get along in a pride without killing each other, unless they are genetically related, and even then: well if you watch nature shows you get the picture there!
Firewalls are a different story; as you can run multiple firewalls on your home network; for example if you are using a modern Cable or DSL modem, most of those today include a hardware firewall as do most Wi-Fi routers you buy from Cisco/Linksys or Netgear for home use. You can then use a software firewall from WD (Windows Defender) included in W10 or most Internet Security suite products such as Norton, Avast, McAfee, TrendMicro, etc. Hardware firewalls are much better at stopping attacks from hackers or cyberpunks; there are so many software tools out there that can penetrate even commercial software firewalls such as stand-along products like Norton's Personal Firewall. Most folks who are home users have this combo of hardware and software firewalls in place.
Business or Corporate networks can have multiple levels of both hardware firewalls via appliance boxes such as Radius servers, PIX boxes, and Gateways, Bridges, and other network segmenting tools such as from Cisco or SonicWALL. These cost from hundreds of dollars into the hundreds of thousands of dollars. Last PIX box I bought years ago cost about $15k. These can be run in multiple layers of nesting in either serial or parallel fashion. Software firewalls in corporate nets are often layered as well, so the servers will be running Enterprise software firewalls, and the PC workstations (Clients) will be running additional Client firewall software. These are stitched together in many different ways to provide a labyrinth of protection to defeat most hackers and virus/malware attacks. So, in todays very common home environment, 2 firewalls are almost always present (1 Hardware, and 1 Software).
Cheers!
<<<BBJ>>>