That part before Clotho is definitely the hardest in GOW2 (on Titan, I remember it being much easier on lower difficulties).
You should really give Chaos mode a shot. It feels like the game is meant to be played on that difficulty. Poseidon actually becomes exceedingly difficult, Hades is still pretty easy, as are Helios and Hermes. You still actually feel that the game lives up to the challenge. The Scorpion is not too bad if you know what to do. Once you see his tail moving you use Hermes boots to dodge them and you are home free. Use up your magic the first time you break his legs and get the O prompt over his head, repeat and then use Rage of Sparta. Chaos mode requires you to be much more resourceful.
What I did to get past the Cerberus breeder and satyrs was kick the puppies at him and dodge his attacks till you get the first head off, then when the satyr came up I used Hades Claws to summon a Gorgon serpent to freeze and crush the satyr. When you get the second head off the dog, use the gorgon again to freeze both satyrs at the same time. It requires a little luck, as you only get two casts per full bar of magic, so you have to get them lined up and be extremely accurate. Once you are only dealing with the Cerberus you are home free.