Green teams! Now, green teams are fun. You can start out with Hobgoblin who has an ability that has nothing to do with green, but it's very fun to use! Ancient Dragon Knight has his own dungeon and you can even make a farming team with him! Actually, don't do that, that died out like a year ago and you won't find any ADK friends. The green Heartbreaker is Cu Chulainn, a gentleman with excellent stats and only comes from the Hero Descended dungeon, which you can't do off the bat. He also occasionally appears as REM chaff when you're rolling for actual non-farmable things. Unfortunately for you, Alraune is garbage so no point farming one up.
Mid Game Team
Wait, what's that, a dragon? Who even does that? Well, mono-green does. Canopus is the boss of Wailing Winds and he is the green Mechdragon. He enhances green orbs with his breath attack and well, since you don't have a healer girl to farm up there's nothing else farmable to really plug in there aside from Canopus or Graviton Earth Dragon. If you do get a Canopus though, this team can take on a lot of things.
Mono-green is similar to mono-blue, it doesn't really have many great things that you can farm to make even better. It does, however, have a lot of very strong REM subs. Also, you can turn half your team into a Cu Chulainn Balance 9x balance team for super easy farming. To wit:
Now that's a speed farming team if I ever saw one.
But back to mono-green, if you find yourself blessed with stones and luck, you can make yourself a nice team.
A team with fast orb changes, heart making for healing or for more damage, short cooldown damage reduction and damage enhance everywhere.