Merrin is nodding along to this right up until the final sentence. 

"....Wait, what? Is - that - is that how the conflict happen? How the one happening right now started? I.....am somehow even more confused, that just - sounds predictably negative sum in a way where I would expect someone to notice and not do it - wouldn't it be cheaper for everyone to, um, agree in advance who's in an overall position such that they would theoretically win a conflict like that, and then just write up a contract with an exchange-of-value that both sides agree is preferable to actually doing the war....?" 

Even as she's saying the words, Merrin is already pretty sure that she's missing something, and also explaining the parts she does understand very badly. 

"Maybe peasants do that? I think they don't have wars with other peasants very often."

Merrin isn't sure if this makes perfect sense or if it leaves her even MORE confused. That in itself seems like a bad sign. 

".....Sure, but why aren't whoever's in charge of the clans on this side of the conflict doing that too?" 

"We can't do trade, Mistress Dath. We're cultivators."

".....Okay, um, never mind." Maybe she can try having this conversation with Wei Wuxian later, once he's awake and less out of it. "Thank you for explaining." 

"The laundry is over here," he says. "People from different clans wear different clothes so you can see what clan they're from. Um, but dath ilan doesn't have its own uniform yet? So for now zhuren wanted you to wear Lan clan clothes, just so you have something clean, and we can commission clothes from the peasants. He wanted black and red which are his colors? But you can wear something different if you want."

Wei Wuxian and Wen Ning in fact both are wearing red underrobes and black outer robes with a red sash and their hair tied back with a red ribbon.

Merrin doesn't especially feel like spending more effort and thought on colors for clothing. "I mean, nobody here is going to recognize a dath ilan uniform even if I come up with one on the spot? So it won't...help, with that. I guess Lan clothes are fine although - I maybe want to know more about the Lan clan before I agree to that?" 

"They have three thousand rules that they're supposed to follow at all times but a lot of them are duplicates. All Lan wear a headband, so it would be pretty obvious that you're not a Lan. They might think you're a servant, except that you're a foreigner and your hair is mutilated, so they'd probably think that someone just loaned you some Lan clothes. The Lan are supposed to be generous with the stranger so that isn't that odd. --Sect Leader Lan is likely to be the only person other than zhuren interested in a foreigner from very far away where they don't have cultivation."

Merrin is trying very hard to listen politely and attentively while noting down all the elements of that sentence and where she's confused so that she can organize her questions and ask them LATER, but her working memory is kind of overflowing. 

"....Right. Thank you." She mostly doesn't grimace. "I - probably should at least know what the three thousand rules are if I'm going to be wearing robes that signal I'm supposed to have agreed to follow them? I, um, what - is the thing people are actually going to expect if they think I'm a foreigner who's borrowing clothes from Lan?" 

Also what the flaming toilet paper does he mean about her hair. Her hair is fine. It's very practical. She had it trimmed like two weeks ago. Wei Wuxian's hair, on the other hand, is a disaster Merrin is not here to judge. 

"That something strange is up and probably they should ask Sect Leader Lan about it? --Possibly we should take you to meet Sect Leader Lan."

"....Right. I should probably meet Sect Leader Lan."

If she's understanding and correctly interpreting the connotations of 'sect leader' then maybe he will be able to actually explain the current situation with its bizarre inexplicable interpersonal (inter-clan??) conflicts that, to her, feel like they HAVE to be a failure of communication except why would anyone fail at that it can't be that hard...

"...Anyway. I am not actually upset about my current clothes," this is mostly true, she is deciding not to be upset because it wouldn't help, Merrin is very experienced at deciding not to be squeamish, "and it can probably wait? I...think I would rather keep wearing these clothes than stumble into some sort of cultural misunderstanding that I don't have any context on." 

"We can go take you to Sect Leader Lan now probably?"

Near the side of the field a teenage boy with a forehead ribbon is stabbing trees with a sword as tall as he is, with a general manner as if the trees had murdered his family. 

He is phenomenally beautiful. Wen Ning would have to facebland, but the stabby teenage boy looks inhuman. People do not look like that. 

Merrin is mostly very asexual and yet that is STILL UNFAIRLY DISTRACTING. Why. 

.....Why is he stabbing trees. Is this some sort of training drill. For what. Merrin....actually does not super want to think in detail about the most realistic training drills for stabbing other humans, but surely stabbing trees is very dissimilar? 

....he could do things to her involving a sword .....that would actually be much more ill-advised than Merrin is comfortable with and also WHY IS HER BRAIN PROPOSING THIS. This is NOT THE TIME. 

She stands awkwardly and smiles at him. 

Merrin is not a tree, and therefore the teenage boy is completely uninterested in her. 

"Sect Leader Lan?" Wen Ning prompts.

Merrin does not really want to go anywhere close to the sword! He seems very focused on whatever training drill he's doing and not focused on avoiding accidentally hurting anyone! 

"...Hello?" she calls out. "Um. Hi! I'm Merrin! I'm a -" okay FINE, "- I'm a doctor from another world! And I'm supposed to talk to you!" 

NO ONE IS SUPPOSED TO TALK TO HIM ACTUALLY.

"--um. That's Sect Leader Lan's brother." He says very nervously, "sorry, Second Master Lan! This useless slave will just be going now. Very sorry to bother you."

Why won't the worst person in the world shut up and leave him alone. He has trees to murder here.

Oh. Is he not the person she's supposed to talk to. Merrin is going to quietly follow Wen Ning away and feel INCREDIBLY AWKWARD, despite the fact that she's telling herself firmly that she had zero local context and thus had no way of knowing that she was being incredibly rude. 

(This doesn't really help. Being accidentally rude is almost as bad as being knowingly rude. At least according to Merrin's emotions, which she has tried very hard to refactor, and thought she had succeeded but apparently she had instead mostly succeeded at UNDERSTANDING THE RULES.)

Wen Ning talks to a servant and then gets directions to where Sect Leader Lan is currently exercising. 

Here are some facts about Sect Leader Lan:

-Sect Leader Lan looks identical to his brother, except that he looks pleasant and happy to see you, instead of like he is about to coldly commit genocide against some trees.
-Sect Leader Lan exercises in nothing but a pair of white cotton pants. 
-Sect Leader Lan can do a one-armed handstand for, judging from the amount of time they took to approach, at least five minutes. He doesn't seem to be breaking a sweat.

Merrin does not normally think of herself as someone who is easily distracted by attractive people! AND YET! To be honest she kind of resents being proven wrong about this!!! 

....She is going to stand there and smile and very politely wait for him to be done exercising. And not ogle his abs. Okay maybe she will ogle his abs a tiny bit. With plausible deniability. 

He notices them, graciously flips into a standing position, and bows deeply. "Good morning, Master Wen. Good morning, Mistress. I don't think I've had the pleasure of your acquaintance," he says, as if it is a perfectly ordinary interaction for a shirtless man to be approached by a foreigner with an obvious translation talisman and vomit on their shirt.