As suggested by bednobs, the police are not best placed to give advice on sentencing matters. Violent disorder is a serious offence. Here’s an extract from The Magistrates’ sentencing guidelines:
“These offences should normally be dealt with in the Crown Court. However, there may be rare cases
involving minor violence or threats of violence leading to no or minor injury, with few people involved and no weapon or missiles, in which a custodial sentence within the jurisdiction of a magistrates’ court may be appropriate.”
Bearing in mind the magistrates sentencing powers are limited to six months custody, I think your solicitor may be nearer the mark.