I was just having a look at the README file for MTW and saw this.

Training Large Units

When you increase the basic size of units they will take longer to train, so that a unit of 200 peasants may take two years to train rather than the default one year.

Can someone explain to me what exactly this means because to me it seems like you can train bigger units than what's available in the game ie. 200 peasants make up one unit instead of the usual 100.