I’ve some first hand experience of this. I’ve been convicted of GBH myself in the past. The problem Evan Williams has is the “intent” part. Laying into someone with a hockey stick is instantly section 20. You’re not avoiding the drop for that.
For context. Mine was section 18, I didn’t have a weapon and I was (legitimately as the judge said) convinced I was about to be a victim of an attack myself.
I got 2 years suspended, 100 hours community service and a fine.