How firm is the recommendation for 8GB mem per vCPU for low volume DBs?

The vast majority of our ITOM customers using Vertica deploy in virtual environments; most often on-prem ESX. Ingestion volumes are typically low perhaps a few GB per day. They frequently disregard the Vertica guideline to have 8 times as many GB of memory as they have vCPUs. The rationale are variations of them not seeing any reason as overall memory utilization is low. For example I just got the the following: "I never saw one vertica host consuming more than 8GB of RAM. In my case, 8GB of RAM per CPU resulted in very high CPU load average." They have deployed Vertica VMs with 12 vCPUs and 16GB RAM.
I would like to hear from Vertica experts whether we should continue to push for them to reduce the ratio of CPUs to memory. For example, in the above would their DB performance improve if they change their VMs to just have 2 vCPUs? As you can see they claimed high loadavg using recommended ratios.