Early game question

Whenever I watch Hera I always see him decide his builds (or at least I see it commonly when he’s just chill playing) when he’s sending vils to berries. I always felt like I had to decide my build before the game because I have to know whether to send 3 or 4 to wood.

I watched Viper do the same thing, and he just sent 4 to wood and still decided scouts.

My question is, is 4 vils to wood on a scout build competitive, like could I wait to decide until I send to berries? Or is it just because they are that good that they can get away with it?