Sun Tzu was even more pessimistic.
> 8. It is the rule in war, if our forces are ten to the enemy’s one, to surround him; if five to one, to attack him; if twice as numerous, to divide our army into two.
> 8. It is the rule in war, if our forces are ten to the enemy’s one, to surround him; if five to one, to attack him; if twice as numerous, to divide our army into two.
You don't have enough forces to overwhelm with a direct attack, but you have enough that you can send half to another location (perhaps a flank attack), while still holding your current position.
And so the method of employing the military—
When ten to one, surround them.
When five to one, attack them.
When two to one, do battle with them.
When matched, then divide them.
When fewer, then defend against them.
When inadequate, then avoid them.
Thus a small enemy's tenacity ~
ls a large enemy's catch. ~