On 40 stamina I put all on left lower starting spot (where 4 are by default already). Gave me 2k5 trophies per run minimum. Thou you say bye-bye to normal chests (still gets the 2 life crystals better one). And better than being fucked and having all squads run on RNG node straight to chests/finish skipping the middle farm entirely.

On 80 stamina I used twice the default setup, and once moved one team to middle spawn (where one is by default). On all 3 I got somewhere around 5k trophies. But as I actually need to pay attention as my 65-75k squads can die here (upsie) I personally prefer to run 40 stamina one and get a bit more exp/stamina (cause exp and level ups will be needed for me in this event hehe, but cant run 10/20 stamina maps cause they seem to yield me half trophies per stamina vs 40/80 ones (34 vs 64)). You could maybe try putting all on middle one to remove as much RNG as possible from getting trophies, didn't test it and with exp/stamina worse I am reluctant to even try.