While it's true Letho and Jacques de Aldersberg don't have much dialogue they are different types of antagonists compared to Eredin or even Azar Javed. Letho is working as an assassin, something that would require a certain degree of stealth and deceit, and so, not making him a viable candidate to extensive dialogs explaining his reasons to go around killing kings and directly antagonizing Geralt. He was more like a pawn in the larger scheme at play for both the Lodge and Nilfgaard. Still he was more of a presence in the 2nd game, directly and indirectly, by fighting him in the elven bathhouse in the 1st act, and through flashbacks in the 2nd act, than Eredin and the Red Riders ever were in this game.
Azar Javed sure might not have much dialogue but he's an ever present threat, he's perceived as the main villain throughout the 1st game until he dies, and you still end up fighting him more than once, learning more about him as the game move forward. This only allows Jacques de Aldersberg a very limited screen time since you spend most of the game searching for a man who you thought to be the main threat when he's just another lackey involved in a much larger plot. Even if there was a lack of dialog it still looked fine in the end as Jacques goes on explaining the reason to his actions.
Eredin on the other hand has been shown as a cryptic character since the 1st game. Showing up several times as a wraith just to question Geralt's actions and how they always take a turn for the worst, taunting him by praising him as his Champion... It almost felt as if the Hunt was always around the corner, watching his every move, expecting him to fail or maybe descend into madness. In this 3rd game however, Eredin seems non existent until the Hunt attacks Kaer Morhen. So suddenly it seems he lost all interest in Geralt even though he seemed quite interested in him and his actions during the 1st game. Which then leads to the fact that the Hunt seems to be actively searching for Ciri everywhere she goes but when she leaves Velen and goes to Novigrad the Hunt doesn't look for her at all as seen in the flashbacks. They only go after her when she arrives in Skellige and once Avalach takes her to the Isle of Mists they vanish yet again. In the meanwhile no one bothers trying to stop Geralt or finding out what he knows or what he does.This makes even less sense if you consider that Geralt ran into the Hunt when exploring the elven ruins where Ciri was supposed to meet Avallach. After that they had to know for sure that Geralt was looking for Ciri and yet no one tries to stop him after that. In fact as far as Geralt is concerned the Hunt simply disappears.
If they couldn't find Ciri it seems kinda obvious they should either look for those who knew where she might be, or at least follow in the footsteps of whoever else was looking for her. At least to me this felt like Eredin was either too arrogant and confident he would get Ciri or he's simply a dumb military leader who did nothing to stop the one threat to his plans, none other than Geralt of Rivia. Then when you finally get Ciri and take her to Kaer Morhen, Eredin is more of a silent observer than a main villain and is completely overshadowed by Imlerith when the latter kills Vesemir in a rather cruel and vicious way that drives Ciri into a mindless rage that nearly annihilates friend and foe alike. Eredin only gets some real screen time at the end and even then he feels more like a secondary character than the main antagonist of the game. This gets an even greater emphasis in the rather anti-climatic fight against him.
Does this mean Eredin should go into a boring endless monologue about how his world is dying and he needs Ciri to give him a child so he could open a portal to Geralt's world and save his people? No. But he should have been used as a means to drive the story forward and maybe even shed some light as to why he was so interested in Geralt during W1 and what happened to him during his time with the Red Riders. This could have been done through flashbacks, when Geralt asks Avallach how he escaped the Hunt while they're talking in the lighthouse or when they arrive at Tir Na Lia.
As it is right now, Imlerith has much more of an impact in the story when he kills Vesemir, creating a much deeper emotional connection with the main characters, Geralt and Ciri, flooding them with grief and at least for the latter a thirst for revenge, all that on top of the fact that the Hunt is a constant threat to Ciri's safety. Eredin on the other hand is nothng more than an inconvenient obstacle that has no real depth as a character other than leading the hunt for Ciri and being mediocre at it.
Don't get me wrong, the game is good, very good. There's plenty of emotional stress at certain parts of the game and the story is well written for the most part. But when it comes to the Hunt -and don't say the game isn't supposed to be about the Red Riders as much as it is about Ciri when you have a large red symbol between Wild Hunt that not surprisingly resembles Eredin's mask, thus rendering the semantics discussion rather void - at times, the Hunt seems more like a secondary plot just there to tie Ciri's character, the badly explained White Frost and how Ciri is the only one that can stop it based on some ridiculous parenting choices (some not so ridiculous).
In conclusion, the Hunt could and should have been given a bigger role to play in the plot and create a bigger sense of urgency to find Ciri. You are told many times that she's in danger and how it's important that you find her fast before she disappears again but that sense of urgency is undermined by not having the Hunt as a more present threat, not only to Ciri but to Geralt aswell.