Lack of $ vs variance from child support

Neg separation agreement now involves couple that earns a little over $40k each with 3 kids and very high childcare expenses. I did a quick worksheet assuming 50/50 split of assets/debt. NET Income - fixed expenses(childcare - insurance -current debt payments - gas -cell phone) would leave each person with ~$650 a month to live off of (food + all other personal + kid expenses + car maintenance +future car purchases (both parties have used cars paid for now)).

Going by the calculator if one parent is awarded primary custody that person will get ~$1000 per month from the other (on top of half childcare and insurance). If its a 2/3 to 1/3 custody its around ~$700 a month. So basically if one parent is awarded any type of primary custody the other parent will not be able to pay their half of debt and have to file for bankruptcy. Since there are joint debt accounts and personal guarantee by both parties on some of the loans the “primary” parent would have to take over full payments or file also. How are situations like this worked out in court? Are they likely to stick to guidelines and let the non-primary go under? We may get a 50/50 cut and it would be a non-issue.

Unfortunately there are no provisions in the guidelines for debt load.