It appears to be a variant of the so-called knockout game and I believe that should be raised to a crime equivalent to attempted murder with 15-25 year prison sentences. It could deter some and reduce the number of these vicious attacks, as well as keeping repeat offenders off the streets until they perhaps had reached an age of self-control.
I doubt this guy will see any sentence over three years but hope to be proved wrong.
From this point, the Justice system is trying to figure out a way to be lenient to him. When my brother was mugged, they told him “We don’t investigate these crimes. Be more careful next time”. If he had told them they are anti-gay MAGA hats that did it, they would investigate it.