If you mean 8 months, I'd agree with you. Men obviously can't breastfeed their children. Once the child is no longer breastfeeding, it is a case by case basis.
I also agree that a 50/50 split is bad for kids. I didn't know this until I went through my divorce and was informed by CPS and literature that having 1 "home" is better for the kids because it provides more stability. Again, which parent can better provide taht stability is a case by case basis.