As nice as the pages in the link are, they do not tell the complete story.
Often a strong magnifier will help you identify the source of a stamp. Sheet stamps show torn perforation ends on all four sides. Booklet stamps show straighter - or even nicely cut straight - edges on one or two adjacent sides. On coil stamps this tends to be the case for two opposite sides. This will not always be very clear on early stamps like yours.
Not even the Hibernian catalogue lists individual coil stamps with perforations on four sides. It does list them with coil leaders.
Looking at the picture, the pair has some very long perforations at the bottom of the right-hand stamp. This would have been the straighter edge in a horizontal delivery coil. At the left there seem to be very long perforations and also the fourth from the bottom at right seems long, as does the central perforation at the top of the right-hand stamp. It almost certainly is a sheet stamp. The single stamp at right seems to have long perforations on all four sides. That also suggests it is a sheet stamp.
There are two watermarks: the 6 December 1922 issue has a big e with an S inside it. The 1940 one has only the big e. Both stamps also were issued from booklets. Consequently, they exist with upright and inverted watermark. Occasionally, sheets were fed inverted into the printing press and even sheet stamps exist with inverted watermark or inverted and reversed watermark.