Yeah mate, it is necessary to have the hub and bearing tight.

Also I have tried as mention earlier and found the differences between std sapph hubs, 2wd sapph cossie, xr4x4 and finally 4wd cossie hubs

Without going into to much detail, for my set up the cossie 4wd hubs have better geometry, and the height of the tca connection gives an extra 35 mm of lowering, without changing the tca and steering arm angles.

Hope what I am saying is understood!!