You are sentenced for what you did, not what you might have done.Actually that isn't true. A person is convicted for the offence (i.e. what they did). However what they "might have done" is taken into account .For example a case of Dangerous Driving where the driver might have killed someone (i..e Prolonged bad driving involving deliberate disregard for safety of others) may be moved from the Magistrate to the Crown Court which has much greater ability to impose a custodial sentence (remember Magistrates require no legal training, just a 12 week training course and some enthusiasm).
Additionally, when sentencing both Magistrate and Judge must take into account aggravating and mitigating factors such as aggressive driving etc in order to determine sentence.
Oh - and re the name thing - he uses different names, to get away with different fraudulent activities. he hasn't legally changed his name.
That's why the guideline for most offences has several bands, relating to seriousness, but the same offence.
If your offence falls into band 2, you are not sentenced in band 1 because you might have committed the more serious form of the offence.
You are sentenced in band 2 - which is what you did.