I got it from the start, in the list of titles, and was chuckling as I opened it. I share your concern. My hipster son talks about XG, possession stats etc but back in my day it was all about trying to score goals and stop conceding goals. Possession is not a factor in itself - last night Millwall has just 27% possession and yet still beat Leicester. It's not how much you have, it's how you use it.
Getting to your issue raised, I'm undecided, like many. I don't think his tactics would work in the Prem, and I fear they may not work next season in the Champo. But let's see what squad he has, as I fear we won't get up through the play-offs in the end.