Sand you have will be fine.
I might consider some root tab's under the sword plant's along with the liquid fertilizer.
Maybe have two of the sword plant's share one root tab, for those planted close together.
At depth of no more than two inches,, I would not worry bout compaction, but would see that the swordplant's are kept from getting out of hand, and robbing nutrient's from other slower growing rooted plant's near by.
Sword plant's I have kept ,send out extensive root's, and I pull them up around every six month's and trim back the root's by about half ,to prevent them from growing too dense.