There is a world of difference between one SAHP and both SAH, in my humble opinion. First, from a practical perspective, the single SAHP has to deal with more isolation and challenging themselves, beyond the fact that their job is now not as 'appreciated' as an income producing job. I'm doing a 'Cliff Notes' version of a response, so don't jump all over me that I am being male chauvinist, but I think it's easier for the wife to SAH vs. the husband. If both parents SAH, there is the medical insurance angle, but there is a whole host of new expectations about how wealthy you are, how much free time you both have, etc. Our neighbors deflected all this by starting a small (money-neutral) business, but it is still very confusing to the 'mainstream' to have both parents at home raising a young family.
But I highly recommend one SAHP, these are precious years that can never be recovered. And young children need a lot of attention. However, where things got interesting for us recently, is that young children grow up and don't need quite so much parenting (we have a 9 y.o. and 11 y.o.). My wife has gone back to work this year and does not want to stop, even though (again IMHO) life was better overall when she didn't work. I think she is looking ahead 2 - 3 years and realizing she needs 'something of her own' as the kids hit their teenage years and get wrapped up in all their own drama :)
Good luck, I'd be interested to hear more about your situation if you'd fill in how you got to FIRE.