I think you're better off putting your spend on the HH Amex card for value since this is your main source of point accrual, however you might actually get more value out of a straight cash back card like the Fidelity Amex or the Blue Cash Amex.

As others have mentioned, the Marriott cards are a (relatively) poor way to accumulate hotel points. The Hyatt and SPG cards each have their own pros and cons, but both those hotel chains have a limited footprint compared to Hilton and Marriott.

The only thing that would benefit you with the Marriott card versus Hilton is if you're trying to attain lifetime status. Attaining the lifetime nights for me, and seemingly many others here, is the easy part; attaining the required point threshold however is more difficult.

Also, the free night cert with the Marriott Premier card which is mostly worth the annual fee.