This would be something to change in EU2, I would vote. Make it where you can load them if you are in port in the same province. Another thing would be to change the way the reorganization of armies works. It would help to be able to select leaders when you reorganize, rather than only being able to split historical leaders by equally dividing your forces, having to move them, recombine them, etc. And of course being able to reorganize your forces during a siege is a must as well.
Somewhere out there, Hartmann, hopefully you are reading this & can add them to the wish list(s) you compile.