The only benefit would be cost wise.
Apart from that if you don't use the same compiler version then you can NOT use the new stuff, as you will not be able to use either compiler to compile the programs.
Example
compiler version - object version (just an example, not real
5.1 - 7
5.2 - 8
6.0 - 9
7.5 - 10
8.0 - 11
If you have the following compilers, in order for the sources to be portable you can not use any instruction that requires a higher object version.
For example if you use the "78" levels you will not be able to compile the programs with version 5.1, as the object level required is 9.
So for the compiler the above is the only problems.
If you are also referring to the runtime, then other problems may arise, specially if you start sharing the files with different version of the runtime.