See section 19.8.7.4, and consider the expression

employee/@name | pensioner/@surname

I would suggest changing rule 3 to make it symmetric with rule 4:

If both operands are climbing, then climbing and the wider of the sweeps of the two operands (Example: @x | */@x)

This would make the above expression climbing and consuming (not roaming/free-ranging as at present). This brings the expression into line with the very similar expressions

(employee|pensioner)/@name

employee/(@name|@surname)