I am not really sure as I have only really properly used a few Eddies though I have loads to choose from. I am still building up several Talisman sets as cant be bothered to regularly swap them around the different Eddies (though doing it more now as upgrading talismans is so time consuming). I tend to use Samurai and Carriage Rider for farming but have also used Soldier, Storm and Grim Reaper too.

I use my Warrior team the most but not on Arena yet so no idea what is needed for that yet though I did just get The Prisoner so hoping he can help on the defence or attack side.