A lot of the writing is understated. Blackadder's final "good luck, everyone" is said calmly and without emotion as the men are about to go over the top. There is a wealth of emotion behind those three words. Anyone watching knows those men are about to go to their deaths and that they know it too. So you don't need lots of words to make a powerful impact on your reader. There is a lot to be said about quiet courage (as shown by Blackadder funnily enough). Think about then what impact you want your readers to experience, then look at the best way of achieving that.
Humour can achieve a great deal here as can quiet acceptance of what is about to happen. Raging against the unfairness of it all can engender some sympathy but I've found a better approach is for characters to fight the odds as much as they can and if they lose, it is clear from the story it is NOT because of anything they've said or done. It is for your reader to conclude that it is unfair on the character, rather than have the character do it (as you run the risk that the character may come across as being whinging).