At those levels of income, the only effect the tax credits will have is on the split, i.e. the relative amounts of your take home pay.
So if you take your half of the tax credits then your take home pay will go up by 3300 and his will come down by 3300. No difference to the total.
What would affect the the take home pay is if you don't split the standard rate band correctly. By default you can both earn up to 32,800 before hitting the 41% rate of income tax. Since you will not be using your full 32,800 you can transfer up to 9k of it to your husband. This has the effect of him earning that amount extra before he hits the 41% rate.
So the simplest way to ensure the optimum situation (in cases where each spouse's money is pooled) is:
Tax credits split - make sure that for each individual, tax credit x 5 isn't going to exceed their earnings.
Standard rate band split - if one spouse will be earning over 41,800 allocate the maximum std rate band to them.