First off to be honest, if i was you, i would get rid of robin hood, odysseus, achilles and get Eris, Agon, Heracles in, but obviously that will take alittle time, you could keep robin hood and settle for Eris, Heracles to get in.
Asumeing you run with Cychreides on Siren (YOU HAVE TO), and weakest horse on Achilles.
Basically pump up Siren with your best equipment posible (except for the weapon, wich you need on Odysseus).
Put on Lochoi or crescent, Odysseus Top front, Robin Hood Top 2nd, Achilles MID, Siren Bottom Front, Hecate Bottom 2nd, (if lochoi Mid 2nd).
But you wanna get rid of Odysseus and Achilles, and get a 2nd Line hitter like Heracles, and start focusing on using Boar Head and Inverted Wedge as 2nd.
You need a 2nd burgler to profit from using siren.
Basically my 2cents would be Heracles, Siren, Eris, Hecate, Agon (or Artemis) and possibly Asclepius as a 2ndary option for swapping with Artemis, or keep robin hood since he will help you on alot of maps later.
For Falling earth, id suggest you get Mounts to G(4)5 minimum, and Cloaks blue or above to G(4)5 minimum, Armors G(4)5 as well.
In the end its a matter of taste, and you can use that setup you have, but it requires alot of upgrades on all of them.
Best answer i can give looking from what you have.