Sentencing advice Sentencing, Plea Bargains

My partner and his Dad were recently arrested for beating up his Dad's neighbour after an argument got out of controll !

The charges against my partner are ABH, Affray and drunk/disordaly. He was arrested and charged with D&D only 3 months ago.

His court date is in 15 days, he only has the duty solicitor that the police provided, and will be sentenced at a Crown court. I have a few questions ( worries ) that i cant seem to find answers for...

He has previous convitctions ( although has never served time in jail ) for things like attempted Arson, Assalt etc the last one only being 4 years ago ( before we met ).

What kind of sentence will ( if any ) he be looking at ? The fella they attacked has vanished off the face of the earth, but im worried his previous record will contribute to the sentencing he gets !!?

I have also been told, that Crown courts are more likly to give a custodial sentence over a majistrate not sure if this is true ?

Im more than positive his dad will recieve an immediate custodial, as when searched by the police he was found to be carrying a knife ( he'dd been doing some DIY at home before it all kicked off ). But what about my partner ?

Many Thanks