I was trying to avoid complexities, 3Ts by simply saying that not all assaults are the same. As a comparison, consider Theft. The offence covers a wide range of seriousness from stealing a £10 bottle of vodka from Sainsbury’s to lifting a lorry load of vodka valued and tens of thousands of pounds. The vodka is just as stolen but nobody would expect the two offences to attract the same sentence.
So it is with assault, but the difference is that different offences exist within the umbrella of “assault”. Nobody would expect somebody who gives somebody else a slap in the pub on a boozy night out to receive the same sentence as somebody who takes a knife to their victim, repeatedly stabbing them and leaving them for dead. Both are “beaten up” but one is more beaten up than the other.
It’s long reading, but the CPS charging practice is here:
http://www.cps.gov.uk/legal/l_to_o/offences_against_the_person/
Very often press reports do not include sufficient information to enable you to see why the matter was charged as it was. There’s often a fine line between the offences and very often a bargain is concocted to reduce the charge in exchange for a guilty plea. But f the offence is clear-cut the CPS will stand their ground and go for the higher charge.