The only difference I can see is that figma_stand has the transparent plastic support beams that the real life Figma series are known for, and figure_stage seems a more general platform for the figure to stand on.
My vote goes to tagging all of these as figure and dropping these 2 tags.
Edit: I see there is also a figma tag with 113 posts. Maybe all figma_stand posts should be tagged figma (should be an implication, but figma_stand has so few posts that I'd say just drop it) and figure_stage should be tagged figure (same).
Maybe an implication from figma to figure makes sense instead?