I just noticed Paramount Plus released a pretty inaccurate compilation video of the different versions of the H5O opening theme music by season.

The correct breakdowns of the various orchestrations by season are as follows:
*Pilot movie (2-hour version) has an extended version
*Season 1
*Season 2 & 3
*Season 4
*Season 5 & 6
*Starting with Season 7, each season had a different orchestration thereafter

Some had more percussion, some had more trumpets, some had a disco flair. My personal favorite version was the Season 2/3 version, followed by the Season 9 version.