You're a soft touch but you want to use metal garden edging in your raised garden bed design. How do you keep the metal from shifting about in soft or friable (that's easily crumbled) soil? You can dig a trench and compact the soft soil (which you need to do anyway as a step in your garden planning once you get to filling in-between the landscape edging.)
Although you hate ramming the point home, hammering metal garden landscape edging into soft loose soil will secure the garden edging. Use a board to cushion the hammer impact and make the border an even height.
If your aim is to prevent pests such as gophers and invasive weeds from getting past your garden landscape edging, hammer the metal garden edging at least two inches below the surface. You do have a metal fist in a velvet gardening glove...and your attractive raised garden design is as smooth and strong as you are.