I think it's great that you do the end of the year financial big picture and that you both are in on all the numbers. That is really good. We do ours more frequently than that but we are in flux trying to work out buying a new piece of real estate and what makes sense for us going forward, as we are trying to accomodate moving to be closer to family but I am unwilling to do that if it means our financial peril.
One thing to keep in mind is that his inheritance is not technically an "ours" item--it is completely his and his to control and use unless he decides to comingle it with your household money, shared money.
We definitely have his, hers, and ours money, and it is based on what we brought into the marriage, as it is a second marriage for both, and there are children involved.
So I am not advocating putting it all into one pot, but I am saying that you have to agree on how you are viewing the monies, and an inheritance is not a joint item unless you choose to make it so.
Edited to add: maybe what I just said is completely irrelevant to your situation; don't know. My mom was a lawyer and all my life, she grilled into me not to comingle inheritances. She will be 94 this summer and doesn't know my brothers sometimes but she knows what she inherited and that she did not comingle those funds!