While No. 6 did seem a bit... over-enthused... his suggestion would work.
Reducing your own casualties is always a priority.
When "honorable methods" will result in greater casualties on your side and a low likelihood of success, and "dishonorable methods" will result in low casualties on your side and a high likelihood of success, and it's supposedly a fight for the very survival of your species...
It's one thing to choose "honor" and die, it's another thing to choose "honor" and so consign your entire species to death without consulting them to make sure they agree that their "honor" is of greater value than species survival.
"They sacrificed themselves for 'honor', but accomplished nothing" makes a great epitaph for a species, don't you think?
Pragmatically, there are times when the ends do justify the means, if the means will actually accomplish those ends.