Ok thoughts:
If you really want to launch SM-1ER and SM-2ER Blk 1-3 missiles you have to have either a Mk-4, Mk-8, Mk-9, or Mk-10 GMLS. (the Mk(s) 8, 9, and 10 are represented on shipbucket with a single launcher). The size disparity between the Standard MR and Standard ER missiles can be seen with this graphic:
I am really not sure why you want both Standard MR and NSSM/Aspide on a single hull, as the only hulls that were so configured were some Marina Militare ships (4 destroyers each of which had a hull 50% bigger than the one you use here) [This excludes the ESSM mounts on the Perry upgrades].
If you really want a single rail launcher, one thing you might consider is the Mk-10, or even a shortened Mk-10 with a shorter booster. This would still not be as compact as a Mk-13, but would let you fire ASROCs without having a pepper box.
I really think before you go any further, you need to think "What roll do these ships play in my strategic planning?" To answer that you need to know the answer to "What is my strategic plan?"