I'm a huge HBA fan (who isn't?) but you'd have to say he needs to weigh in with 12+goals for a couple of years and/or perform to consistently high standards for another 18 months or so to make NUFC legendary status.
Pedro did it over 250 games for us. He delivered consistently, to a very high standard over many games.
If HBA continues the way he's started his NUFC career then there's every chance he'll be up there.
What a player.