Hudson, Wood and Buerhle are excellent top 15 pitchers that should give you lots of production. However, I would recommend pulling a trade if your offense is strong to pick up a fourth solid starter so you can forget about having to use Foppert, Chacon and Eaton. Foppert is totally unproven, and if he doesn't improve soon, he's going back to the minors. The Giants can't afford to keep a struggling pitcher in their rotation. Chacon has been great so far but I think its a mirage and once he starts pitching at Coors in the heat of the summer, he will come apart, like virtually every Rockies pitcher does. I watched the game Eaton pitched today on WGN and he looked impressive, but he also has been inconsistent, they have been running his pitch counts too high for a guy just off surgery, and he won't get many wins on a hapless Padres team.
I would far rather trade away some excess offense to get a fourth pitcher you can count on, like a Glavine, Moyer, Leiter, Pineiro type guy so you can forget about worrying about those three garbage pitchers.