Additional inclusions like Desolation Twin, Elder Deep-Fiend, or Oblivion Sower can overwhelm the rest of the table with more worrisome spells than they will know what to do with, while also supplying an effect that cant simply be countered
Control and midrange pilots often consider these to be some of the best dual lands in MTG for their ability to convert mana into threats without diluting spell density
Vexing Shusher, Dosan the Falling Leaf, Prowling Serpopard, Archetype of Endurance, Spearbreaker Behemoth, Stonehoof Chieftain, Boseiju, Who Shelters All, Cavern of Souls, Homeward Path, Domri, Anarch of Bolas, Heroic Intervention Protection
While mentor was a nicely functional mechanic with a couple breakout constructed cards, it didnt really make for interesting play patterns
It offers unmatched redundancy if one ramp piece gets removed, you have a dozen replacements and its land-based acceleration creates a permanent advantage that compounds over time