The Cdn Gds don't appear in the Order of Battle so regardless of the disbanded vs. laid-up debate they don't have any real standing. When they were active they were a Regular Force regiment and took their seniority from that. In fact, as a Guards regiment they were immediately senior to any other Infantry regiment.
The uniform of the Cdn Gds was of special interest to the Queen. Files at DHH show her interest in everything from buttons to rank badges. She had a special concern over the Cdn Gds wearing the Star of the Order of the Garter (worn by the CGG and GGFG s well as British Guards regiments) so the proposal was made to design a new, 10-pointed, star representing the provinces. If this were done today I would like to think that the 6-pointed, snow-flake Star of the Order of Canada would have been used as a rank badge.
Because the Cdn Gds were to be the senior regiment in Canada it was decided that they would wear their buttons in singles. Notwithstanding this, it was agreed that the CGG and the GGFG would continue to wear the pattern of uniform worn by their British affiliated regiment. Although the two Militia regiments never wore Cdn Gds insignia they were re-designated as; GGFG (5th Bn Cdn Gds); and, CGG (6th Bn Cdn Gds)