No, they are not.
I see many people struggling without green packs. Strange, I have never had the same problem. The situation when I have to recover my team with greenies between the games happens 0-2 times per season when the schedule is really unlucky.
If you need green packs to stay afloat, you are doing something wrong. Maybe you are training the whole team for bonuses? It is a waste of 15-20% with videos, and twice this amount without. It is pretty much possible to do bonus trainings without 2x videos and spending precious green packs.