Deductions & credits

So we are both on the loan and we pay from a joint account, so I believe we meet those requirements/best practices.  Where it makes a difference is that I own 2 other properties and if you add up the mortgage loan values on those 2 plus 1/2 of the 3rd property i am under the 750 threshold and hence I get the full advantage of the deduction.  If I take 1/2 the interest and put the mortgage value in as the entire value on the tax statement I get limited out by being over 750k...

Does this make sense? The overarching question is if I only take 1/2 the interest shouldn't I also only have to take 1/2 the limit burden?