Battle of the Hornburg

[Meres]

When Théoden and Aragorn led a vicious cavalry charge out of the keep, there were only few soldiers. Did most of them die before retreating into the keep? Just before retreat into the keep there were soldiers everywhere but suddenly only few.

[Old_Begonia]

To be honest, I'd have to have another look at the film. I've seen it many times, but not recently. As I recall, the rampart down which Theoden, Aragorn, & company ride is not very wide. A war horse, fully accoutered and mounted by an equally fully armored rider, takes up a bit of space, so I'm not sure how many more soldiers could reasonably have followed at once.

[Denethor]

This is the point at which Théoden has his "it's over" moment - the implication being that very few remain. The subsequent charge is indeed down a very narrow rampart.