The 'Safety Advisory Group' is a nonsense, and basically the excuse that clubs use to reduce allocations. Clubs don't want visiting teams having an impact atmosphere-wise.
That's where these reduced allocations come in, and why Sunderland and Newcastle get away with putting away fans miles from the pitch (against PL rules).
The Premier League need to start getting tough on shit like this. They could start by telling Newcastle that their ground doesn't fit with the PL criteria, and that they either get it sorted or they risk relegation. But they won't.