This idea isn't even a particularly new or unusual one. When faced with a superior enemy, fighting opportunistically is an old as dirt strategy. People have continued to use it for literally millennia because it's effective.

Force is tilting the balance of power to your side by gathering advantages. Warfare is the Way of deception. Therefore, if able, appear unable; if active, appear inactive; if near, appear far; if far, appear near.

If your enemies have advantage, bait them; if they are confused, capture them; if they are numerous, prepare for them; if they are strong, avoid them; if they are angry, disturb them; if they are humble, make them haughty; if they are relaxed, toil them; if they are united, separate them. Attack where your enemies are not prepared; go to where they do not expect.

This strategy leads to victory in warfare, so do not let the enemy see it. - Sun Tzu, The Art of War

Relatively speaking, I'd say 'our enemies' are extremely strong. Probably best avoided (for the moment) if the overall objective is victory.