Biff! Pow! Etc!
This shouldn't work, because nothing really happens. It should feel like padding, like "oh crap we've got an issue to put out and we're really late and let's just have a meaningless punch-up", because that does happen sometimes -- spoiler alert -- but Dann and Roy Thomas pull it off.
I think it works for two reasons. First, there are flashbacks throughout that break up the fight and provide context for why it is happening; I wouldn't go as far as saying it's clever, but it is at least more interesting than a strict linear narrative would have been. There's also some nice bits with the rest of the Avengers also having their own low-level disagreements that reflect the main fight, although the motif is perhaps laid on a bit thick and makes the team look somewhat dysfunctional.
The second reason it works, and probably the main one, is that the Thomases put in the effort to characterise Hawkeye and US Agent so their dispute not only makes sense, but has a sense of weight to it. It's not your standard superhero misunderstanding, but a conflict that develops out of the two of them being dickheads. Moreover, they are both dickheads in their own distinct ways, which come across well in the writing.
Less effective is Scarlet Witch at the end saying that "it would take every ounce of power we could muster" to stop US Agent if he "ever turned bad", which seems like a bit of an exaggeration given the Avengers have beaten Korvac and Thanos, but okay Wanda, whatever.
The success of the comic rather depends on how much you care about Hawkeye and US Agent. I admire the Thomases' restraint in not positioning either of the pair as being right, but making them both utter douche canoes makes it a bit difficult to engage, even if the argument is well-written. It's an interesting issue that shouldn't work but somehow does. Three Cables.
During the testing it is discovered that Cap may have a weakness to extreme cold, which is something I don't remember seeing anywhere else and doesn't appear on any character profile I can find so I suspect it was dropped at some point. Probably the moment this issue was printed.
As Captain America is a tactical genius, he decides the best way to test this new theory is to go to "the north magnetic pole" to find his missing pal, D-Man. There he fights -- and is defeated by -- a giant snow snake (!), bumps into his old friend Jack Frost -- basically Iceman with hair -- who is dragged underwater by the giant snow snake, and then Thor turns up to deal with the situation but is unable to find the giant snow snake or Jack Frost, so the two Avengers shrug and leave. Is Jack Frost okay? They don't care. Should we have a look around for D-Man, since that's why we're here? Nah, we've fought a giant snow snake, that's enough for one day. Again Steve, wow.
I'm trying to be somewhat charitable with these reviews, because 1991 was a different time, and comics were different, and the pressures of a monthly schedule mean that not every issue can be a perfect work of art, but this is tosh. It feels like filler; most of the issue is a fight with a mindless monster, and you could tell the story with any character. The only specific ties to Cap are Jack Frost and D-Man, one of whom contributes nothing and the other is forgotten. On the plus side, the art is solid with some good storytelling, but the Arctic setting means that there's a lot of empty, white space, which again suggests a rush.
Two Cables, and that's being generous.
(Spoiler: the Warriors don't even know the answer!)
I understand this is a superhero topos dating back to the early days of the genre, but it's also a stupid one and I would have hoped that by 1991 it had gone out of fashion. Unlike Avengers West Coast, there's little attempt to add context or texture to the fight; the characters punch each other until everyone's on the ground then Emma does her passive-aggressive and haughty thing, and that's your lot. Maybe it reads better if you've been following the series, but as a standalone issue it feels either inconsequential and uninspired, or a weird throwback to an earlier era.
I've never been a huge fan of Mark Bagley's art style, which I know puts me in a minority. There's something about the way he draws faces that puts me off, a sort of weird horizontal stretch that gives everyone a sort of batrachian look, but I can't deny that he's a good storyteller and he makes the big, pointless fight at least visually interesting.
I'm not going to say this is a bad comic, but it is dull and devoid of ambition and like the Captain America issue doesn't even resolve it's own setup. Perhaps I'm expecting too much of 1991. Two Cables.