Seems like the US equally waged war on both Fronts.
Surprised no one answered /u/J2quared here.
The majority of the Navy was in the Pacific because the Pacific is mostly ocean. The Navy wouldn't be able to march on Berlin, but it certainly was capable of bombarding the Japanese shore in 1945.
Next, the Navy and Army weren't equal in size. This breaks down how many men served in each branch by year:
| Year | Army | Navy | Marines |
|---|---|---|---|
| 1942 | 3,075,608 | 640,570 | 142,613 |
| 1943 | 6,994,472 | 1,741,750 | 308,523 |
| 1944 | 7,994,750 | 2,981,365 | 475,604 |
| 1945 | 8,267,958 | 3,380,817 | 474,680 |
22% of the Army in 1943 was 1.54 million people - almost as many as the ENTIRE Navy in that same year.