Without the exact numbers, nobody can tell.
Depending on their age difference, it can be advantageous to draw two independant payment, or tag one onto the other (take 'half of spouse'), or delay one and/or the other spouse's benefits. Without all the exact numbers, it is impossible to say which option is optimal.
You can download a little program from the IRS website, where you can enter your payment history, and it will give you the exact payment you will get for each choice. It is still a lot of effort, and if you are not savy with optimizing many numbers, you should go see a professional about it. I have had multiple times the chance to get this optimization calculations done for free, with recommendations on which of their assets to invest in (which you are free to ignore after you walk out). Try around some larger companies like BlackRock, and they might offer it to you. Of course their interest is that you like them so much that you invest your 401k with them afterwards, but again, you are free to not do it (just don't say so from the beginning on).
A guess for your situation would be that the older spouse files immediately, and takes the relatively lower payment while waiting for the younger spouse to reach 70 (and get a relatively higher payment), and then switch to half of that. But again, depending on your exact numbers, that might be not optimal.