I’ve actually used the Proteus-Triton-Gadeirus trio in War many, many times.
For a team solely around one Family, I don’t have 5 4*/5* in any one Family together — the closest I could come is Proteus/Triton/Gadeirus/2 repeats (I have 4x Proteus, 2x Triton, 2x Gadeirus maxed), or Inari/Danzaburo/Sumitomo.
Maybe I could try doing 5 of the same Class. 