Were are you located?

I have been using strawberries in a similar situation. Mine have sayed alive all through this harsh winter and look good when in bloom and taste even better.

Vinca minor - periwinkle - does best in rich soil and in shade. It is also an aggressive spreader in many areas.......to the point of being invasive. Groundcover junipers would certainly work - they love sun and tolerate pretty poor soil, as long as drainage is good.

The strawberries are a good choice. Ornamental or sand/beach strawberries are grown specifically as a groundcover - actual fruiting strawberries (like you buy in the store) may not be happiest in your poor soils.

Yes, vinca is quite aggresive along the Gulf Coast.

I mixed garden soil in the bags into the existing soil for the strawberries. Then covered with pine straw and leaf mulch. Have everbearing and June bearing. Once they got established they spread like crazy.