Rollitup

Depends on the current you run them at. You can work with 4 running them at 2.1 amps, will provide over 800 PPFD.
6 at 1.75 amps, more efficiency and higher PPFD (1080).
8 at 1.05 amps, even more efficiency, less wattage and a respectable PPFD of 935.
6 at 2.1 amps = over 1200 PPFD (you may need to dim them a bit).

Thanks for the reply! I like the sound of running 6 at 1.75. Will a MeanWell HLG185-C700B work for all of those or should I look at the C1400B or something entirely different.

at 1.75 amps = 62 watts each so you would need two HLG-240H-C1750B drivers, 3 on each to power them. You can also fit 6 on a single HLG-320H-C1400B for 300w total.

I think I would go the HLG-320H-C1400B route. If the cobs were to bright I could use a dimmer to lower the amperage?

A dimmer is always a good idea, but 300w in a 3x3 will be good at full power.