I've deleted GW's flagcons, and cited MOS:FLAG as the rationale. Deleting the rank images may be a different story because like you say, images can be helpful to the reader (as opposed to decorative).  In GW's case, his General of the Armies 6 star ranking is unique.  Accordingly, including it in the infobox is probably ok; but the WP guidance in the regard is vague.  I think the reference to images in the infoboxes is meant to include images of the person and nothing more.  The GW infobox template is Template:Infobox officeholder. It has no guidance in this regard.  The officeholder talk page has 16 pages of archives, so I did not research it.  In any case, because GW is such a unique figure, I think deleting the stars would only rankle many editors.  Considering that GEN Ham may someday be an officeholder or 5 star, I would not fight restoring his galaxy. But my personal preference for him is to omit the stars.