Should our league be asking for Additional Insured status?

Yes! If another entity is providing services or participating in your event (i.e. a league with different insurance, a caterer, or half-time performer), they need to provide a COI listing your league as an additional insured, since you do not have control over their operations and do not want to take on this added risk. Request COIs from other leagues or vendors at least 30 days in advance of your event.