Just an objective honest criticism, I feel this show could have done much better in casting in general . I know they are fictional characters, but usually in biopics when they get actors for roles, they go out of their way to make them look like the person. Daniel Day Lewis as Lincoln, Tom Hanks as Walter Disney, Rene Zellweger as Judy Garland, Jamie Foxx as Rey Charles just to name a few.
I just feel that whenever a person is playing a role that is so well established be it a fictional legendary/iconic character like Spock or a real person like Lincoln, they need to do better with the casting appearance, make up and hair styling .et.c to make them appear more like what was established on physical appearance. There needs to be some kind of look alike even if it is not much.
Paramount + Star Trek just does not seem to care. Dr. M'Benga, looks nothing like the original actor, he is suppose to become in 10 years, also for the actress who plays chapel. the original actress had a more heart shaped face, while this new actress face is rounder. Paul Wesley looks nothing like William Shatner. His jaw bones are too sharp and his handsomeness is more broody and mysterious (I know this from the vampire dairies days when I used to watch the show) Shatner kind of handsome was more all American man, even in the most generic of terms.
I would strongly recommend never comparing a film's practice to that of a television show, even an expensive one.
First there are a ton of historical characters in film who bare literally no real resemblance to the actual real person they are playing. But those that do, have three significant options.
1. Casting someone who has a strong resemblance to the characters.
2. Using makeup and hairstyling effects to bridge the gap.
3. An actor going to the extreme of major weight gain or loss or muscle development or loss to make them more fit the part.
And in quality productions any of three can use physical mannerisms of the real life person (if wide based visual footage remains), and vocal inflections to help match the vocal mannerisms of that person.
1. Is obviously the easiest , but its also the hardest to cast. There are many actors but some aren't going to want to relocates one aren't going to work in the format you are using, some don't want to be in the type of production you are making. Some don't want to work as a series regular. Some will work a miniseries, but not a series that is going to produce year after year. Then you availability, you have talent level, you have if the fee is agreeable.
2 and 3 are definitely factors that are far, far, far harder to manage on a tv production schedule.
Actors who physically change their own body take months to do so and its a significant strain on them, To do so for a film some are absolutely willing to, but to do it for a longer production, is far, far, far less common to see done in practice. You must also cast with significant lead time to allow this to occur, something also not typically arranged for a tv production.
That leaves option 3, option three can work but its far easier to manage on a film production schedule. Films typically produce 2 to 5 minutes (some far less) of usable footage a day (unless you are working some lower budget or indy productions). The level of detail for makeup to really make a character for standard tv is almost impossible, because normal television has to produce for more usable material every single day (thus the actor needs to be available on set, versus getting made up in the chair). Take Trek (pretty much all of it, films and TV) they make aliens based on working with a person. They aren't doing the reverse, using a specific person and turning that actor into them. It's much more time consuming. So even characters like Worf, Saru, Nellix, Quark, ect have their makeup made for them and they create the character around what works for their face and the amount of screen time that person is going to be in.
Now premium tv (which Trek is) has a production schedule more generous then standard tv, but its still far more strict them quality produced films. They could handle it if they had to, for characters that aren't going to be used much, but doing it for bridge crew, people who need to be on set a majority of the time. Not going to be practical. Not to mention even the development of the appliances is going to be far longer for a film then for a tv show.
I mean look at The JJverse, the majority of the cast bear no physical resemblance or even facial structure of the character they are based upon. People sang the praise of Urban and Pegg and they don't have the physical shape or the facial structure of the original actors. Quinto had some of Nimoy facial structure but not his physical shape and not even close to his voice. Yelchin has no facial similarity. Saldana didn't have the right facial structure, and a different physical shape. Yet most complaints about the films had little to do with the actors in it.
"fictional legendary/iconic character", and then you mention M'Benga a character who at best was on screen maybe 12 minutes.....Sorry but in no way shape or form does his character even come close to being in that class. In fact the only character that absolutely makes that cut in SNW would be Spock. I wouldn't even put Uhura in that group, and certainly not Chapel, M'Benga, Number One or Pike. As for the casting of Kirk (for next year) yes he does. But without knowing the role of the character its way, way to early to be worried about it.
You use Tom Hanks for one role, but Hanks has played over 10 real life people in major films, and most of them he doesn't look like the person he's playing. Either wrong body type, or wrong facial structure, and in most of them outside of costumes and an adjustment of hairstyle (sometimes) he doesn't match the character. And I can look at these people and see other actors. But there is a reason they cast Tom Hanks. Streep will rarely do prosthetics, but her ability to match voice and mannerism is outstanding so producers couldn't care less if she looks different then the real person. And those are for quality film productions. You get to tv, and the vast majority aren't going to look too similar to the real person.