I've watched the first 3 episodes of Fargo, season 4. So far the series is shocking in its mediocrity. My guess is that Noah Hawley --the chief writer/creator-- had been pressured into a 4th series due to the success of the first 3-- a project which he was not really inspired to do. It shows.
When one starts with an unbelievable premise --that rival ethnic mobs would exchange sons in order to keep the peace-- but without sufficient quirky or off beat humorous writing to overshadow that premise, all that's left is an awkward, ridiculous story. A good example of a silly premise, but with stellar off beat writing to support the silliness would be Anderson's The Grand Budapest Hotel. For Fargo season 4 it would have been better had the Coen Bros. --who executive produced-- had been directly involved in the writing.
Chris Rock as the negro mob leader was grossly miscast. One expects him to crack jokes every time he speaks, due to his forte, which is comedy. There are probably 20 guys with more gravitas that they could have hired. Likewise Jason Schwartzman as the inherited leader of the Italian mob is not believable. His comedy chops are there, they just don't fit into this series with its misfire writing.
One standout is Ben Whishaw, who plays "Rabbi" Milligan, the eldest son of the Irish mob's leader. He's an outstanding actor, and is one of the few characters with good dialogue. Mention must be made of the part of Oraetta Mayflower, a nurse played by Jessie Buckley. Her role is shoe-horned into the story as the woman who is pressed into killing the Italian mob boss. It's not clear yet whether she's just an accommodating murderess, or whether she's simply a psychopath who enjoys killing folks. There again the writing is uninspired, and she tends toward over playing.
So far the outstanding features of this production are the phenomenal cinematography, the set designs/locations, and the costuming. Most period films exaggerate the colors of the automobiles, the street scenes, the clothing styles, the commerce of the day-- all in polychromatic Technicolor. Here the photography could have actually been filmed live in the 1950s.
There are 8 more episodes to go. Can it improve? Yes, but the writing and directing will have to get better in order to allow for it. IMO it's a safe bet that there won't be a season 5.
~Doc