That's the price of having rigged helms, I'm afraid. Non-rigged helms will deform in order to accommodate the face morphs, rigged helms don't. I made those helms so that they won't clip with all but the most extreme face morphs, but to fit faces with the sliders put at maximum values would have required me to alter and scale the helms to unrealistic (and ugly) proportions. Having a helm that doesn't lose it's shape, and doesn't clip with the neck, is a worthwhile trade off for having some clipping with the extreme face morphs (still shouldn't happen very often- I've got an army of 50 guys wearing these, and I haven't noticed any face clipping...).
However, if you really want to have the helms behave like the native ones (i.e. not rigged, and deforming according to face morph), then you can use the helms called 'inv_***' as the main helm reference. Just use a line from one of the native helms as your module system entry, and reference the 'inv_***' item instead. The lods won't work with that, though (at least I wouldn't think so).