I've been a Navy spouse for more than a decade (eep!). I'd be happy to correspond with her and try to answer any questions if she'd like. Be forewarned that I'll give honest answers, whether they are favorable of the Navy, or not. Send me a PM if interested and she and I can chat that way. My husband is an aviator, so I can't speak about the SWO lifestyle specifically, but the Navy and those support systems you mention I can do.
Some things to think about. IME, horse people are fanatical. There are going to be significant costs associated with schleping a horse from Rhode Island to San Diego (or whatever). Make sure you really think that through before you make any promises about her horse "always" coming with you guys. And if you end up overseas, forget it. No horse. Also, most military housing only allows 2 pets (and many have breed restrictions as well), so keep that in mind. Even if you have no intention of living in military housing, the military can have different ideas. You get an overseas assignment to a place with mandatory housing, and it's Sophie's Choice for your wife. I believe Air Force policy is similar--two pets in housing.
Your second post mentioned that because the Navy knows that missions are difficult, they have support systems. We are at a joint base right now, and my observation is that it doesn't seem like the Navy has better/stronger/more support systems than any branch. Mostly, you have spouses clubs, and the robustness and value of those depends entirely on the command. Some are great, and some are nearly non-existant or are exceptionally dysfunctional. They are run essentially entirely by the volunteer efforts of spouses so how much time goes in to them, what kind of events they have, general culture, and pretty much everything else vary based on who is passing through at the time and who has stepped into leadership roles in the group. Be careful about assuming they will be there to cradle your family while you are gone. They might be, or they might be simply a monthly meeting, a contact roster, and little more. One group for the same command could even be both of those as CO spouses and other involved spouses change during your time. I have a friend who was the wife of an Air Force officer, who stayed in long enough for command and post-command tours. He wasn't RPA or aviation, but her experiences with the spouses clubs seems to be fairly similar. As for programs outside the spouses groups, they are few and far between. Occasionally there are some "how to write a resume" kind of offerings, and there is access to mental health care, but that's about it. From your post, I get the impression maybe you think the support systems are more robust than they really are.
I am not a church-goer, but I do think that most military communities, especially the more distant or remote ones, have strong church communities so that will likely serve you and your wife well.
I won't step outside my lane and give you advice on your two choices, even if I had advice to offer. But as a general note, you are the one who has to go to work everyday and do the job. Both are going to have a fair amount--or more--of suck, and of course you and your wife are a team and should make decisions accordingly. But in the end, her having you home a bit more isn't going to be better on your marriage if you are miserable.
