Here is my analysis for what it is worth to add to what you have said:
Not telling you how to suck eggs disclaimer, this is for people that might not get the fundamentals of league yet (any quotes and corrections or improvements welcome with this post-lets help each other out, share the knowledge rather than drop jargon and leave...).
There are two main ways that halves play in formation (traditional stacked or linear formation and the modern way of split halve's I will explain using our halves). And in the last four games we have seen clear bias towards one over the other.
Traditional Linear or stacked halves formation:
Halfback is first receiver (means what it say's almost always gets the ball first from the dummy half who is usually the hooker). The stand off (real name for five eight) gets the pass from the halfback or is the second receiver. If the Ruck is ground 0 then the pass to the halfback is 1st receipt, pass on to Stand off is 2nd receipt or to put it another way. Dummyhalf - halfback - Stand off....it is that simple.
This is how Tanah and CHT play, the old way, stacking one side of the field to create an overlap (Roosters game, everyone raves about CHT and RTS because we have a formation that is going to load up the left all night) Boyd even scores on that left side by using the Roosters anticipation that it is going to keep going wide on the left, then Tanah holds onto it and cuts through a hole made by Cherry Evans who is too slow to chase inside out.
And as we know using stacked halves or same side halves, we turned out normally dead left side attack into a million dollar looking backline.
We need to remember that CHT and Boyd had all offseason to practise and know each others games. We need to caution overreaction here to what happened with Luke last night.
So along comes Metcalf and the game plan changes to the other formation that halves play - the modern way - "split halves"
Why? because this is now a new combination and they are making Metcalf's return as simple as possible (good call Andrew Webster) "Mets you run our right Side - Tanah you make the call when to go right".
But that is not all there is to it. A major part of a halves roll is direct the forwards in how, where, and when to run. And that aspect of a half's game is quite complicated for both the half and the forwards being called onto the ball.
That takes familiarity and a lot of practice. But done well you will see halfbacks form close bonds with specific forwards, especially your wide running forwards.
It all comes down to communication as demonstrated by the legendary Shaun Johnson here:
View: https://youtu.be/2Ilgo6BYE3s?si=HUCbOFwL9yHKfIaq
So it is easy for fans to say "why don't they just switch around and do what they did last week?" which I get it....it is frustrating....but you have to remember the reason Metcalf and Boyd can't "Just play like CHT and Boyd" is that there are multiple moving parts to that stacking that Boyd and CHT run, and that takes time together to develop.
And lastly, Webster had a huge call to make this week, how to protect Boyd's form and to protect Metcalf's return to the NRL. He chose to split them and thereby give them an easier platform (for Metcalf) to familiarize himself with his portion of the team, those players on our right.
Webster himself has been quoted as saying that the clubs halfbacks have been working on split play potential which gives you a lot of information. It means Webster is fully aware that his halves have major work on's to reach that Nirvana of Halve's play "the stacked half - split half variation" first pioneered by the great Peter Stirling and Brett Kenny (Stirling was an organizer Kenny had lightening speed and started popping up anywhere on the field, sound familiar?) they were the first two to do it successfully, but it wasn't called split halves yet.....that term started to appear around the time the legendary pairing of Stuart and Dally (there is a reason Dally is mock nic on this forum).
Excuse the history lesson people.
Long story short, expect to see Webster force Boyd and Metcalf to play split for some time and grin and bear it, he obviously wants them to ground out an understanding of their respective 'side's of the field before becoming a 'couple' first date is awkward......
Here's a tip....when you see Metcalf pop up on the left, get excited, real excited, it means that Webster is happy to pull out the Nuclear option.