"The Pacific" wasn't as good as "Band of Brothers". While entertaining, the premise that Tom Hanks used was historically wrong. Japanese imperial expansion was well-known before the Pearl Harbor attack. The Japanese had clearly shown their savagery and brutality, even against other asians; the "rape" of Nanking is but one example. They were going to expand, either to Siberia, to the north; or Singapore and other southeast asia to the south, depending on Nazi Germany's success against the USSR.
While there is no doubt as to Sgt John Basilone's heroism on Guadalcana, his character was not anchored to later USMC campaigns, such as Cape Gloucester. With "Band of Brothers", Richard Winters was the central character, and the rest of Easy Company's members were fully developed. In "The Pacific" the three central characters, Basilone, Eugene Sledge, and John Leckie, just didn't have enough experience in the overall campaign. "With The Old Breed" and "Helmet For My Pillow" were too narrowly told to give a broader picture.
The Pacific campaign was just too large, and the various campaigns were given short shrift in an attempt to keep the series to ten episodes. "Band of Brothers" limited itself to a core of one company, and the series didn't attempt to expand to a coverage of the entire European campaign.