Yes, you can easily sub out a Mountain for Sokenzan, Crucible of Defiance or Shinka, the Bloodsoaked Keep without hurting your mana base, but doing so decreases the effectiveness of payoffs that specifically need Mountains to work
This includes sacrificing and reanimating her, although its important to note there is no possible timing that lets you reanimate Sefris with her own effect
Next up is
Shanid, Sleepers' Scourge, or myriad other decks that want to be able to recast legends from their graveyard.
Wrap Up Soul Warden | Illustration by Randy Gallegos Lifegain strategies have plenty of support and enablers, even if it isnt the most competitive archetype in the game
Compare this with a card like Lavinia, Azorius Renegade which costs two mana and its tough to envision the card seeing play outside of mono-white decks