This. Specifically, the mention of Caesar reminded me of the beginning of the Gallic wars, when the Helvetii tried something similar: http://classics.mit.edu/Caesar/gallic.1.1.html

> When they thought that they were at length prepared for this undertaking, they set fire to all their towns, in number about twelve - to their villages about four hundred - and to the private dwellings that remained; they burn up all the corn, except what they intend to carry with them; that after destroying the hope of a return home, they might be the more ready for undergoing all dangers.

Spoiler: It did not work out so great for them.

You can have highly motivated people get themselves killed. Just because burning the ships produced motivation doesn't mean you'll have victory

literally all life is based on survivor bias

While this is true, it’s probably a bad idea to rely on human reproductive evolution when strategising a battle.