[selectodude]

>1) Not everyone wants to use iLO or whatever equivalent another OEM provides.

Then you aren't an enterprise because they're absurdly useful for managing dozens/hundreds/thousands of systems.

>3) What about RAID cards like the P420 (not the P420i) that either aren't hooked up to a management engine or are from an entirely separate OEM?

There's a reason enterprises standardize on a common infrastructure from an OEM that supports everything in the box even though you could go on Newegg and build your own systems for thousands of dollars less.