Yes, they both perform different tasks, so the person from McAfee is full of it. Honestly, even free, I wouldn't use McAfee's VirusScan. You want to cripple your system's performance, install VirusScan on it and watch it take a 25-33% hit overall. Compared to the less than 10% hit pretty much any other virus scanner out there causes.
I us AOL with McAfee. After experiencing a very slow computer with continuous "connected, but not responding messages", I downloaded Malwarebyte's Anti-Malware. It detected 232 infected files which were quarantined/deleted and the problem was fixed. I contacted McAfee about this, because I always kept it updated, and their tech dude told me to remove Malware, because it was in conflict and was giving fake alerts. I never got a straight answer on why Malware corrected my problem if the infected file alerts were fake. Is it OK to use both McAfee and Malware?