The head tightening sequence has a minimal effect on the gasket itself, but tightening up (or loosening) in the wrong order can break the camshaft into about 4 pieces, and this can happen even if you do it in the order suggested in the manuals IIRC. The head should always be pegged at EP when tightening/loosening, and whatever order you do it, small increments are the order of the day.
I have my own sequence which I have used since I started, without a single problem, but due to the possibilities of something being lost in the description and causing other people problems, I'll keep it to myself.