I have considered that.What you say is definitely true that the term 'schultz' (originally 'schultheiss') was a term for a sort of German communal headman.And although it's now pretty archaic (none of my German friends have ever heard of this word), it does seem to have been in current use in Volhynia around time of which we speak.
But on balance I tend to think Eugenia's interpretion that it is referencing a family name is, in this context at least, a little more likely.Novohrad-Volynskyi was at that time, as she says, a larger and more ethnically diverse town, rather than a small German farming colony where I imagine the office of 'schultz' would apply.
It's really kind of hard to say for certain.The article is written for a very general audience, and doesn't seem too specific.It is not clear to me whether the 'Schultz house' stood, at the time it was erected, within the bounds of the city proper, or perhaps some further place that was only later on incorporated into the city.
But it could be even more complex than that.The article seems to imply that there were about 600 Germans in the city proper, and I have read some articles, talking in a very general way, about small numbers of Germans settling in Ukrainian urban centers and establishing some type of industry, such as cloth mills, breweries, etc.
It's possible that you are correct.Even if there was only a small community of Germans in the city proper, come in as industrial workers, it's possible that they set up a formal 'schultz' for themselves.
But my guess is that the 'schultz' was more a rural, farming phenomenom, where people lived communally.