I'd put Romulus in tier 2.
I finally got to watch this since it's streaming on Disney+ now. I'm in complete agreement with your ranking with the caveat that I don't remember much about Alien 3 and it's been a while since I've seen Resurrection.
Goes quite high on the gore stakes, probably more so than most Alien movies, and is definitely the 'slasher horror' mode of Aliens (where Alien was more classic horror, Aliens more war horror, this is slasher horror). It starts slow for the first hour, then the second hour is all screaming and running and dying.
There must be something wrong with me because I didn't think it was all that gory. Which is odd given this movie included the most graphic acid on human scene we've seen. I'm starting to think I'm just dead inside.
That said, with only 5 characters there isn't that much dying--and I can only name two of the characters (Rain and Andy).
I'm in agreement here. In the first two movies, Ressurection, and even Covenant I felt we had a chance to get to know some of the characters. In
Alien, Brett and Parker are even complaining about their pay to Dallas, just a nice little slice of life a lot of us can relate to. I only cared about Rain and Andy. I also didn't care to the callbacks to the other movies. Kane, I mean Rook, telling the doomed teens they had his sympathy or Andy telling the alien to "Stay away from her, you....."
That said, it was perfectly serviceable. No Alien film is ever going to be a genius piece like the first two were but I'm happy with a solid movie.
I did think it was interesting what they boys in the lab were trying to do with the xenomorph DNA. It was a nice twist on the "perfect" being and nice to see them trying something besides a bioweapon. You're right, a perfectly serviceable movie about sums it up.
One thing I noticed... Alien movies typically use characters' last names -- Ripley, Hicks, etc. In this one we're very much on first-name terms with all the characters. I don't know that it matters, except that I noticed it.
The big difference here is they were all friends. These weren't coworkers or fellow soldiers they were friends who had known one another for years even if there had been an apparent falling out. One thing I noticed was how young everyone was. In
Alien, Weaver was the youngest actor at the ripe old age of 29 whereas the actors in
Romulus ranged in age from their early twenties to about 30 for the actor who played Andy.
(Though I've seen a fan theory that actually the 'adult' alien on the Nostromo actually had been an adult for a long time, having originally burst out of the navigator on the derelict ship on LV-426. After Kane got face-hugged, the adult alien followed the crew back to the Nostromo and somehow managed to crawl inside. Which solves the 'how did it grow so fast' question, but now introduces the 'how did it not starve' question.)
In the novelization by Alan D. Foster, the xenomorph got into the crew's food supply. But if it ain't on film it might as well not have happend. For this movie, from face hugger to bursting seemed to go much, much too quickly. I don't have an exact timeline for how quickly Kane went from hugged to burst, but it wasn't less than an hour.
I do think it as in poor taste to use the image of Ian Holmes for Rook. Just disrespectful and unnecessary as any synthetic life would do. In the first movie, the whole crew is surprised to find out Kane is an android. If there are a bunch of Ian Holmes lookalikes running around out there the chance of discovering the company's subeterfuge in replacing the Nostromo's science officer would have been more likely to be discovered.
