Hi,
"Does this fit in the rule of thumb 50 < 80, or does having the 4 JobServers really indicate 200 > 80?"
This would be 200 > 80 and cause the CrystalReportProcessingServer to work at max capacity without any spare bandwidth to meet, for example, view on demand.
I'd suggest you to set CrystalReportsProcessingServer's "Maximum Concurrent Jobs (0 for automatic)" to 0 and let CrystalReportsProcessingServer to determine the optimum capacity it can afford per your machine resources using its own algorithm. You can see the optimum value from "Maximum Child Processes" in CrystalReportsProcessingServer Metrics.
At last, lower the "Maximum Jobs Allowed" from CrystalReportsJobServer to match the Maximum Child Processes" in CrystalReportsProcessingServer.
Also, you just need ONE CrystalReportsJobServer instead of FOUR CrystalReportsJobServers, but increase the "Maximum Jobs Allowed" so that there is only ONE parent process and multiple children workers to save you system resources from the reduction of extra 3 parent processes.
Hope this helps,
Jin-Chong