I'm not sure I'm doing this right... The card is not unique. It's a boon but it doesn't have to be earned right? I can just throw it in any deck. It can be 3x in a deck.

Can I equip multiple of them on a single hero? Could multiple support for the eagles use the same eagle's stat?

Support of the Eagles has the 'Boon' trait, but it is not a Boon like the ones in the LotR campaign (it was released two years before the LotR saga expansions started, so well before the whole Boons and Burdens concept was devised), it's just a regular player card that you can use like any other.

It is not unique, restricted, or limit 1 per hero, so yes, you can attach multiple copies to the same hero, and you can have each copy target the same eagle or different eagles, as you choose.

Wow... pricey but powerful... thx