HeadoftheHive - not sure you are really clued up on this, to be honest.
The only way the ops husband has been able to progress his career (with working away), is by having the op at home looking after the children.
This was how my divorce was viewed. Very high earning husband (over £100k), who would never have got that far in his career if I hadn't been at home, looking after the kids. I did work part-time for most of it too, but had very little flexibility as I teach. My earning capacity stalled as I couldn't take on more hours, or responsibility whilst being the only person at home to do everything.
Consequently, I got spousal maintenance (as one of our kids was a baby & I wasn't working at that time), a mescher order (he pays my mortgage & we sell up when the youngest is 18 with a 67.5% equity to me) & maintenance. The spousal maintenance was short term to enable me to get back to work.
My exH pays a relatively small amount of his earnings to me, whilst living a largely childfree life. He lives miles away so still gets to bail out of drop offs/pick ups & mid week overnight stays & also actually has a life - childfree evenings, getting out the house in the morning easily. My earning potential will always be compromised as my kids already have one largely absent parent & I refuse to be another one - as it stands, I do work almost 4 days in a very demanding job, with plenty of prep on top of that, so my kids don't always get the level of attention I'd like. I still can't get a mortgage as my work is regarded as temporary & I don't earn enough to get anything around here anyway.
50/50 is ridiculous as the majority of women's careers take a back seat once children arrive.