I think you really need to consider which beings you're forcing in the same sacred space. If dedicate an altar to both Jormungandr and Thor, do you expect the energy to be harmonious or even productive?
I have one altar. On this altar I have statues to Odin, Freyr, and Thor, the gods I am closest too. I also have amber beads for Freyja, stone carvings of animals for my guides, and many other things. They all work together, do what feels right, but always practice with a measure of logic based on the lore.