In OTL, when the Estates General of 1789 were called, the Third Estate was granted numerical representation twice that of each the other estates. This was highly unexpected a considered a victory out of the blue for reformers at the time. Later it emerged that voting by estate would neutralise this numerical advantage, but expectations had now been raised, and it caused the Third Estate to demand they all sit and vote together. Aware of their numerical majority, they declared themselves the national assembly, feeling comfortable to invite the other two estates to join them.
But what if the initial representation had not been granted? What if the Third Estate turned up in Paris with only a third of the delegates? Would they continue to sit separately? They has some sympathisers in the First Estate: would they gang up on the nobility by protecting the Church from taxes or some other deal? Would reforms get through? If so, how much more moderate would they be?