If you want to choose one size for all pointers, there's no need to declare each variable as near or far. Instead, you select a standard memory model and your choice applies to all variables in the program.
Summary: A standard memory model provides default sizes for all pointers.
One advantage of using standard memory models is simplicity. You specify the way the compiler allocates storage for code and data only once. Another advantage is that the standard memory models do not require the use of Microsoft-specific keywords such as __near and __far, so they are best for writing code that is portable to other (non-DOS) systems.
The disadvantage of standard memory models is that, because they make global assumptions about the environment, they may not provide the most efficient use of memory for a particular program.