SNMP Monitoring Dell Hardware without Openmanage

I have used OpenManage in the past. But, I'm at a new employer and they already have systems running without the OpenManage software installed. I've been tasked with monitoring these servers. Some of the servers I have access to the DRAC, some I don't. Couple of Servers have VMWare ESXi installed.

I just basically need one question answered about some observations I've had trying to monitor Dell servers without OpenManage installed.

With respect to the PERC controller on Dell Server, there is no way I'm going to see the status of the PERC controller without OpenManage installed to expose the PERC oid's. Whether it's through the DRAC or a direct SNMP poll of the server.

 Is that a true statement?