All HLG metal cased drivers will self ground through the frame if it is mounted to the metal frame. If you mount the driver directly to the metal frame, theres no need for the additional ground on the AC side. Its when you have the driver seperate from the frame that you need to add the wire to the frame and to the green earth ground wire on the AC side.
That hlg 185H-c1400 is a perfect driver for (4) 1212's. You will run about 200W (50W ea cob). Its exactly what I use right now on multiple different lights I built...
(4) citi 1212's on that same driver:
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CREE CXB 3070's on 2 of those same drivers
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