As far as grievances go, I would give the advice of this.

The company began awarding and training captains out of seniority order not long ago. There is an adundance of guys senior to the group of new hires who have already begun receiving capt pay. If you are an FO in or awaiting upgrade training, reach out to your ALPA reps and ask about being pay protected because the company went out of seniority order.