generally i would recommend the one with the lower compensation to claim all dependent exemptions.   say the higher income taxpayer claimed all.   withholding would normally be a higher % of taxable wages of the higher income taxpayer.   if that taxpayer were to claim then all the withholding could be reduced to the point that you are subject to underpayment penalties.   however, this is just a generality. 

what you could do to check is to use TT taxcaster to estimate your taxes.  this wouldn't give a perfect estimate but it should be close enough.   this is based on 2019 tax laws.   there are proposals in Congress to further reduce taxes in 2020 for individuals but no one knows if this will ever pass   

https://turbotax.intuit.com/tax-tools/calculators/taxcaster

once you get your tax estimate you can use the TT withholding calculator and try various scenarios

https://turbotax.intuit.com/tax-tools/calculators/w4/

understand these are only estimations.  if your wages vary during the year you should revisit and recalculate

you can then submit new W-4's to change withholding

you can avoid penalties  no matter what you tax is for 2020 if you meet any of these tests. I'm going to assume you are not going to pay estimates

1) withholding covers 90% of 2020 tax

2) withholding  equals 100% of 2019 tax (110% if adjusted gross income over $150,000)

3) balance due after withholding is $1,000 or less