Tugs usually do not tow. They push.
This is because pushing is more mechanically efficient than pulling. When we pull, there is tension and slackness in the ropes, and the attachment between the trigger and the pushed one keeps changing.
But the metaphor becomes far more interesting when we think of leading instead.
A bird at the head of the flock can lead 100 others if they are enrolled in the journey. That bird would never be able to pull (or push) even one bird, no matter all of them.