Was there an SAS-like unit in this period?
Short answerRogers' Rangers are probably the closest comparison, though they should not be treated as a direct modern equivalent.
NotesRogers' Rangers are identified as the nearest comparison available within the game's period when a viewer asks about an SAS-like unit. Empire: Total War does not let them operate in the way that analogy suggests. The comparison is therefore functional and approximate. It is a starting point for thinking about specialist formations, not a claim that an eighteenth-century unit was institutionally equivalent to the modern SAS.