Pushing snowballs is a cute sentiment, albeit an incomplete metaphor, but it is also quite romanticized as depicted here.

I get that it is about cooperation, "pushing" and growing the size and impact of organizations, but applied to the wider world it quickly becomes complicated; the snowballs interact.

Everyone is pushing multiple snowballs over complex terrain. For many their snowballs are melting as they roll them, sometimes actively counteracted by institutions or higher powers.

And don't forget that huge snowball we all roll around on, called earth, because it's losing snow...