As soon as you deal combat damage with Rith, you can create a good amount of 1/1 Saprolings, giving you defenders for a potential counterattack
Big, durdly creatures are key here and I think thats the way you build around this guy which is good since Boros is traditionally about tokens and small creatures
Thats the part of Reanimator that makes things fun: you arent simply getting monsters from your Graveyard and putting them into play, you are usually wanting to target huge, game altering monsters (literally and figuratively) that easily take over the game state, placing your opponent on a usually insurmountable backfoot
This could have been the herald of Izzet Artifacts and had a version of this card existed even a year earlier, they could have been an upgrade from Kurkesh, Onakke Ancient for those who were looking for this kind of effect
Nearly half the assortment under $20