^ Thanks!
Instead of scratching your head, you may have tried to read the rest of the sentence
I read what you said. I'm just telling you what I disagree with what you said. Stand alone, as Jinx indicates, to me means it has little or no impact into the season. Because it's a time-travel episode where a reset was hit, means it has no impact to me.
What impact did Sim's existence and fate have on the rest of the season?
Sim's confession to T'Pol led directly to
Harbinger, and the fact of his existence haunted Archer and caused him to do something foolish (which ended up advancing the arc) in
Azati Prime. So, I don't think it's accurate to say that
Similitude had no impact on the rest of the season. It shaped characters' choices down the line.
Having said that, I do agree that someone with only a passing knowledge of ENT's S3 could sit down and enjoy - even understand - the entirety of the story without extensive explanation beforehand. In
Similitude, the mission is the clock ticking in the background, not the focus of the story ("Earth needs Enterprise; Enterprise needs Trip."). In
Twilight, T'Pol's exposition to Archer sets up the conflict enough that a casual viewer would at least get the gist, if not the details. I contrast that with, say,
Countdown, which requires pretty detailed knowledge of the episodes preceding it. To me,
Similitude and
Twilight (along with
North Star, Doctor's Orders, and
Extinction (
ugh!)) are sufficiently understood as stories all by themselves to be considered standalone, even though they may have subtle repercussions that show up later on in the arc.