If the imam of the Eid al-Adha prayer is poor can he sacrifice an animal in place of somebody else?

Usually the community is only allowed to offer their sacrifice of Eid after the imam of the Eid prayer has offered his sacrifice. My question is if the imam was unable to afford the price of a sheep is it still necessary that he offers the first sacrifice and if so can he offer a sheep in place of somebody else? (If you could explain the views if different fiqh schools that would be great)