I don't put much stock in Giambi's DH/1B splits, as that's a function of him happening to play DH more in the first half last year, and first in the second half. I'm not sure what you heard about Duncan, but his stats indicate that his OBP and slugging percentage are both under .300. The Yankees are second in the league in runs allowed, so that's not their problem. Even if it were, Jose Veras and Colter Bean are available.
Here's an ideal Yankee lineup, looking at BPro's projections...
C- Posada
1B- Pena
2B- Cano
SS- Jeter
3B- Rodriguez
LF- B. Williams
CF- Damon
RF- Thompson
DH- Reese
The trouble is that two of those guys are in Columbus. Miguel Cairo is not a better hitter than any of the scrubs currently in the outfield.
Andy Phillips is never going to be a MLB player. Ever. He's been given chances over the last two years and still can't hit anything but a fastball, and he has no plate disipline.
That's an awfully harsh assessment. His projections peg him as a .255 hitter with a .317 OBP. That's not too good, but it's something in the meantime. It's not like Bubba Crosby has ever hit MLB pitching. But then again, Carlos Pena's still hitting in Columbus too.
I'm sorry, but until he learns to hit a breaking ball or any other pitch beside a fastball hes just not going to be very succesful.