The question on nuclear modernization is a general question on the military budget, not detailed and specialized questions. Ordinarily, the President submits a budget request to the Congress, so it is expected of Presidential candidates what their major defense budget proposals would be.
Certainly Republican primary voters deserve more details than "We're going to make our military so big, so strong and so great, so powerful that we're never going to have to use it," and "I will be so good at the military your head will spin."
BS. The various capabilities of those three nuclear delivery systems are very technical and specialized. And OMB prepares the budget and how much input any given president might have can vary enormously.
These recommendations would come from the Pentagon and Join Chiefs, and the president would just review the recommendations and make a decision, or accept whatever was recommended.
I doubt one primary voter in 100 has ever given one thought to the nuclear triad. As I've said several times: Hugh Hewitt showing his ass, asking questions that don't belong in that forum.