Doesn't sound like Greenacre is an assistant. Might be a video analysis + other job?
Fairly hefty demotion if that's the case. Greenie is obviously a top bloke to still be involved.
He's recognised his own limitations (as per last season) and is keen to learn under new gaffer. Good on Greenie and I wish him well. Rado Vidosic also took a similar path himself so is hopefully likely to mentor Greenie.
I heard he was demoted because he didnt want to change his surname to Greenašić