An easy trick is to use a flat blade screwdriver and use that to turn the nut whilst spinning the wheel - this will give you a nicer feel when you are tightening it screwdriver tight (I am imagining you are not the hulk in green mode).

once you are done with backing and tightening it about 10 times whilst the wheel is spun - you note the position of the nut, now loosen it and advance the nut just enough that you feel resistance (hold as strong as if you are holding a baby canary) - note this position. Advance the nut abt 20% ahead of the first position. and smack the snout of the spindle to test the freewheeling of the bearing.

I have done this a lot of times on a number of mercedes bearings and they always work silent. Dont worry too much about the grease going dark between the rollers, I have been told that its normal as long as the grease doesnt smell burnt and has not separated to oil and soap cake. (I used regular american red wheel disc brake grease - not the fancy minty german stuff) - I drove both my car tens of thousands of miles on a bearing service and they were silent as church mice in a library. (the mercedes FSM also speaks of the grease and bearing races turning dark)

using the correct amount of grease is also paramount too as the hub acts as a centrifuge as it turns

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)