Can an elephant ever be more useful than an advisor in xiangqi?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Yes, and it depends entirely on what is attacking. Against a horse-and-soldier assault, the elephants are doing the essential work, covering the points a horse wants to land on, while the advisors contribute comparatively little. Against a chariot-and-cannon attack the relationship flips, and the advisors matter far more.
Matching the defender to the attacker
Before deciding which pair to protect at the cost of a soldier, look at what your opponent's remaining attacking pieces actually are. A defence that has kept both advisors but lost both elephants is in serious trouble against horses, however solid its central file looks against cannons.
Why this nuance gets missed
General advice tends to treat "keep your defenders" as a single instruction, when the two pairs guard against genuinely different threats. Knowing which pair matters more in a specific game is worth more than any blanket rule about defenders in general.
Related questions
So there's no single answer to which pair is more valuable?
Correct, it is purely a function of what the opponent still has to attack with.
What if the opponent has both horses and both cannons?
Then both pairs of defenders matter, and losing either one opens a real hole.