He chose Dicky and Oswald as guides.

So we led him to the ambush, and we went through it as quietly as we could.

But twigs do crackle and snap so when you are reconnoitring, or anxious to escape detection for whatever reason.
Our Colonel's orderly crackled most.

If you're not near enough to tell a colonel by the crown and stars on his shoulder-strap, you can tell him by the orderly behind him, like 'follow my leader'.
'Look out!' said Oswald in a low but commanding whisper, 'the camp's down in that field.

You can see if you take a squint through this gap.' The speaker took a squint himself as he spoke, and drew back, baffled beyond the power of speech.