I am really hoping that if there is a new magic book with scenery, that GW is going to take a long hard look at how many of the factions are organized. If magic becomes a stronger and more important game play aspect, a faction that only has access to magic through allies will have less choice in list construction i.e. free peoples/beastclaw raiders.
I feel like many of the factions reek of 2016 AOS. Why are collegiate arcane/ironweld/free peoples different factions? Thank god Firebellies are their own faction, right?
My prediction? Racial allies. Should you include an ally that shares a race keyword with your allegiance race, they do not count toward you allies point total. i.e. Human, Ogor, Duardin, Grot, etc. But they still have allies restrictions. (Can't fulfill battle-line requirements or be generals, etc.)