Sending a unit through the desert to capture a town which your not too sure is going to be defended or not IMO is in the spirit of the game and in the type of conflict at the time. High risk = high reward.
I would be pretty confident that this is not the only scenario where this could occur.
Strategiclayabout does make a good point about poorly mapped terrain and angry local populace but you could also say that a thousand very thirsty, hungry and desperate german cavalrymen would be pretty motivated to overcome a village which may only contain a small garrison.
A rule change may be very difficult, or unnecessary depending on your viewpoint, to implement for SCWW1 but maybe it should be noted for its next incarnation.