hi Ray,
Thank you and I am happy my comments are found useful
As to your questions, when settling precedence there was distinction between the Guards and non-Guards. The First Regiment of Guards always came first, followed by the Coldstream Regiment. For example, the Welsh Guards were formed only in 1915, but took precedence as 5th regiment of guards, thus before any of the 'normal' regiments of foot.
Thus, before, during and after the WSS the Guards outranked any of the regiments of foot at all times!
Orkney's Regiment of Foot was indeed formed in 1633, but as a mercenary regiment for service of Louis XIII. According to my research it does not originate from any Scots unit in Swedish service, though absorbed remnants of these regiments in 1634 (I think) when campaigning in the eastern parts of modern day France. It came on the English Establishment for a short period in 1661, and took precedence from that time. The regiment remained in French service until 1678. The regiment comprised 21 companies in 1678, and was split into two battalions in early 1686.
The regiments of foot guards had of course many companies allowing the formation of several battalions. This happened of course, but these battalions were not permanent. They can be seen best, I think, as 'purpose only' battalions formed by grouping several companies. (The battalion as we know it, as an administrative entity, is from a later date) The battalion of guards serving in Flanders from 1701 is such an example, and the various battalions of guards in Spain were formed in a similar way (together with the Coldstream Guards). In the early years of the NYW the First Regiment of Guards was split in even four battalions.
I have not examined in depth the etymology of the word battalion, but my impression is that it has its origin as a means to measure army sizes in the field of battle with a battalion anywhere between 500 and 800 men composed of a varying number of companies (a captaincy, the building block of regiments of varying size, Prussian companies were large, Dutch and English companies were small). The word battle is obviously in the word battalion. Squadron is in that sense a similar way of counting cavalry; for cavalry the troop (the captaincy) was the building block with squadron being the tactical/battle field unit of measurement.
Hope this all makes sense
cheers,
Wienand