Ok, the 22.3 CAN do the inside air recovery work on the undifferentiated "HUB/SORT" half of his 22.3 job description, but management has no right to ASSIGN him to do that over your objections. By objecting to his taking over your work you notified management that you considered the inside air recovery work a "preferred job", and under National Master Article 22 they had to put it up to bid, which bid you, as the most senior employee, would have won. Grieve it, ask for lost hours. You should win unless your local BA fails to represent.
Is this guy a NEW 22.3? I thought management was holding back on fulfilling its obligation to create those.
Oh, some driver who didn't get the opportunity to do the retiree's work given to some putative carwasher also has a grievance. You might want to talk to some of them if management gives you any guff.