Yes, I admit that keeping those three realtime protection is a bit overkill. Personally, AppGuard would be enough.
But I decided to keep the three to cover the two stages of protection. First stage is the pre-execution protection. And the second stage is the post-execution protection. AppGuard and Kaspersky would deal with the first stage. AppGuard, Kaspersky, and HMP.A would deal with the second stage. There is a third stage, which is the post-infection remediation, which Macrium Reflect covers.
I'm not an expert at determining whether a file is malicious, so a help for post-execution is needed. Yes, I know the obvious things about malware. But, I'm not adept at dealing with the unknowns. This is why I use Kaspersky and HMP.A to monitor and block any malicious software I might run manually.
I also believe that HMP.A has a superior anti-exploit protection than Kaspersky's. So, even though Kaspersky has its own anti-exploit module, I decided to keep HitmanPro.Alert.
In the end, though, AppGuard is enough to protect me, and the other two are just there for post-execution monitoring.