The Expanse - Books and Show

Marked as spoilers for those haven't seen the series or read the books. If you care about one but not the other, or don't care about spoilers, then...

There's usually a discrepency between a novel and a TV or movie treatment unless the positions are reversed (the novelization of a movie), but this case has me really perplexed.

At the end of the first book, Holden convinces Fred Johnson to use the Mormon ark ship Navoo to ram Eros, which has started moving towards Earth to complete the (theorized) original mission of the protomolocule. However, the Navoo misses the moon, which requires someone to head down there to set off some nukes that will alter the course. Miller volunteers thanks to his obsession with Julie Mao, who he finds somewhat alive on Eros (a coincidence I just realized in typing that). Instead of crashing into Earth, the moon crashes into Venus where the protomolocule instantly sets to work doing...something...beneath the dense cloud cover.

So WTF is going on with the TV adaptation? We left S1 with Miller still alive, so at best we can say that the series season isn't 1:1 with the novels. Though if I remember correctly, S1 ended with Miller and Holden on or having just escaped from the Eros lockdown when they start to get an inkling of the protomolocule plot. So maybe things are going to be on track after all.

But S2 promos seem to focus on the second book in the series, which starts on Mars. In fact, knowledge of what the protomolocule DOES is really important to that intro, so if they don't cover the completion of the first novel, I don't know how they're going to explain the start of the second.

But they've already modified the hell out of the novel for the show. In the book, the Roci crew was never as antognistic to one another as they are in the show (especially Amos, who takes to Holden as the new captain pretty quickly). Also in the book Avasala uses swears like everyone else uses vowels. She's WAY more badass than she is on TV. The book doesn't go into the stealth technology investigation as much as they do on the show, and Havelock doesn't get gored by mobsters on Ceres.

I'm wondering why the serious modifications. The book was really tight and they could have filmed it as-is without serious trouble (aside from Avasala's language). I'm certainly not dissapointed in any way, as there's enough similarities to make connections, and both are superb, but I'm more curious than upset at the weird disconnect between the two.