You need to know how the character is written regardless because the stroke order is part of the character. There are some basic rules like working left to right and top to bottom. Also, each component has the same order when written out.
I also seem to recall there's been successful input system like this for Japanese, in particular for handhelds with pen input (think psion and similar early devices).
Optical recognition of Kanji can be though, but with stroke direction it is easier.
