>>>His solicitor said this will go to Crown Court
Did he say
why? Cases generally go to Crown Court for the following reasons:
1. There are complex legal issues involved, which the Magistrates think they aren't qualified to deal with. (I can't see that being relevant here).
2. The defendant pleads not guilty and exercises his right to be tried by a jury, rather than by the Magistrates. (From what you've written, that also seems to be unlikely).
3. The Magistrates are of the opinion that, if the defendant is found guilty, their sentencing powers won't be strong enough. (i.e. they consider that a prison sentence of greater than 6 months might be required).
So it seems likely that the solicitor is of the opinion that the offence could result in a substantial prison sentence. However that seems rather odd as you appear to have described a 'Category 2' offence (with 'lesser harm' but, because of the use of a weapon, 'higher culpability'). Where a first-time offender is convicted after a trial, the Judge must work from a 'starting point' of 26 weeks imprisonment and then vary that (depending upon the circumstances of the case) up as high as 51 weeks imprisonment or as low as a 'low level' Community Order. If the defendant pleads guilty custodial sentences can be cut by one third or, for example, a 'low level' Community Order substituted in place of a 'high level' one.
My guess is that the Magistrates might well decline jurisdiction (and pass the case to the Crown Court) but that the Judge will then pass a non-custodial sentence (or pass a custodial one but suspend it) as Judges usually do their utmost to keep first-time offenders out of prison.
Pleading guilty at the earliest opportunity will certainly speed things up (and reduce the chances of a custodial sentence) but it usually takes many months for any case before the Crown Court to reach a conclusion. (9 to 18 months is common for 'not guilty' pleas but even where the defendant pleads guilty cases can still take many months).
See pages 11 to 14 here to read what the Judge will have before him when considering sentencing:
http://sentencingcouncil.judiciary.gov.uk/docs/Assault_definitive_guideline_-_Crown_Court.pdf