Of course that would be great but the problem is that it's a game. Thus there will be many more enemy ships in the ocean in the game compared to the actual numbers in the war (check Uboat.net you'll see there where many boats which didn't see any enemy at all). In SH3 there was a Spy satellite mod which showed all the contacts and convoys, there where probably 40-50 convoys around at all times, while RL there where a lot less.
An other thing.. we as players will take more risk than they would RL. resulting in more daring attacks on BB's and/or Aircraft cariers. We could most likely kill the complete navy from the British in year 1 of the war