One of them (Evoking) represents card disadvantage in exchange for efficiency, and once you start to cast Solitude for its full cost you will get the opposite, a two for one
I like it a lot in a Lathril, Blade of Elves deck, but really any Commander with a tap ability in green should be considering this
Also, Ran and Shaw gives you twice the number of dragons
Reanimation effects are powerful because they can get a creature from your graveyard directly onto the battlefield often at a lower price than that creature's original casting cost, allowing you to intentionally dump your best creatures in the graveyard, then bring them back for a lower cost
This is to help you stabilize to give you time to win the battle and get your Serra Angel, I mean Serra Faithkeeper
Interestingly, in the case of Winter Orb and Trinisphere, the effect only applies when the Artifact in question is untapped