Honestly, theoretically, I think the O'Carrick siblings would be similar to my experiences with my siblings, but without the murderous intent.
We're kind of estranged despite living in the same house. When the family does get together, even when it starts out happy, it often times ends up in arguments. I don't think I'd miss my siblings that much when I move on. With one of them, their voice just. Grinds my gears. I can't listen to her sing (most of the time, except when a game is purposefully made for that).
(TW describing strangulation for the next paragraph only; the two after that reference it)
.... Another thing, too, though, is that I did strangle my sister once because, I think I don't remember for sure, I was overstimulated by her and wanted her to shut up. I didn't know it would potentially kill her, mind you, I just saw media doing it (you know, like, looney tunes). The last things I remember from that moment is her face as I was doing it, my mom finding us behidn the recliner, and staring guiltily as my mom consoled my crying sister in the bathroom.
I can see this happening between Halt and Ferris because Ferris just. Talks a lot. But Halt wouldn't know it was a murderous type thing because of reasons other than media, mainly being his environment itself.
(TO BE CLEAR I do love my siblings because they were born in the same family I was and my family and I do have a lot of good moments without arguments. The above paragraphs are just pointing out stuff that is similar, and I can't really describe things THAT accurately. Additionally, the second paragraph's events happened more than 10 years ago and we get along normally now).
Despite all this, I always imagine them pretty different: more connected and tight-knit, actively supporting each other, actively thinking about each other when stressful situations come up.