I support a change in this entry.
a shop steward is traditionally the steward of a shop. a shop in this sense refers to a workplace which is organised in the trade union sense, that is, has union representation. the steward is the leader of the shop union, and is the person workers contact when they have questions to the union or problems with the employers.
the shop steward is referred to as the section secretary, i.e. the local representative of the trade union.
we have to be careful here, not to mix up the concepts of union as understood in Germany, and the concept of union as understood in GB, for instance. Germany has 7 or 8 unions representing a lot of workers according to the type of work they do - metal, chemical and so on.
GB traditionally has many more unions, many representing single trades, the spoonmakers union as example.
Comparisons are not easy to make.
whether the German Betriebsratsombudsmann or whatever is comparable to shop steward is dubious, since the German titles suggest a differentiation in what these people do, that is absent in the English shop steward.
I would suggest, as the most basic unit, that the German translation should be: betriebliche Gewerkschaftsrepresentant/vertreter.