diff --git a/lambdas/functions/control-plane/src/aws/runners.test.ts b/lambdas/functions/control-plane/src/aws/runners.test.ts
index 4243e4b06b..82f31295be 100644
--- a/lambdas/functions/control-plane/src/aws/runners.test.ts
+++ b/lambdas/functions/control-plane/src/aws/runners.test.ts
@@ -511,13 +511,15 @@ describe('create runner with errors', () => {
   it('test ScaleError with multiple error.', async () => {
     createFleetMockWithErrors(['UnfulfillableCapacity', 'MaxSpotInstanceCountExceeded', 'NotMappedError']);
 
-    await expect(createRunner(createRunnerConfig(defaultRunnerConfig))).rejects.toMatchObject({
+    await expect(
+      createRunner({ ...createRunnerConfig(defaultRunnerConfig), numberOfRunners: 3 }),
+    ).rejects.toMatchObject({
       name: 'ScaleError',
-      failedInstanceCount: 2,
+      failedInstanceCount: 3, // numberOfRunners when zero instances created
     });
     expect(mockEC2Client).toHaveReceivedCommandWith(
       CreateFleetCommand,
-      expectedCreateFleetRequest(defaultExpectedFleetRequestValues),
+      expectedCreateFleetRequest({ ...defaultExpectedFleetRequestValues, totalTargetCapacity: 3 }),
     );
     expect(mockSSMClient).not.toHaveReceivedCommand(PutParameterCommand);
   });
@@ -543,6 +545,18 @@ describe('create runner with errors', () => {
     );
   });
 
+  it('returns partial instances on recognized scale error instead of throwing', async () => {
+    createFleetMockWithErrors(['UnfulfillableCapacity'], ['i-partial']);
+
+    await expect(
+      createRunner({ ...createRunnerConfig(defaultRunnerConfig), numberOfRunners: 3 }),
+    ).resolves.toEqual(['i-partial']);
+    expect(mockEC2Client).toHaveReceivedCommandWith(
+      CreateFleetCommand,
+      expectedCreateFleetRequest({ ...defaultExpectedFleetRequestValues, totalTargetCapacity: 3 }),
+    );
+  });
+
   it('test error by create fleet call is thrown.', async () => {
     mockEC2Client.on(CreateFleetCommand).rejects(new Error('Some error'));
 
@@ -688,12 +702,14 @@ describe('create runner with errors fail over to OnDemand', () => {
     // fallback to on demand for UnfulfillableCapacity but InsufficientInstanceCapacity is thrown
     createFleetMockWithWithOnDemandFallback(['UnfulfillableCapacity'], instancesIds);
 
+    // Partial success: 1 instance created, unrecognized error for the rest.
+    // Returns partial instances instead of throwing to prevent orphans.
     await expect(
       createRunner({
         ...createRunnerConfig(defaultRunnerConfig),
         numberOfRunners: 2,
       }),
-    ).rejects.toBeInstanceOf(Error);
+    ).resolves.toEqual(['i-123']);
 
     expect(mockEC2Client).toHaveReceivedCommandTimes(CreateFleetCommand, 1);
 
diff --git a/lambdas/functions/control-plane/src/aws/runners.ts b/lambdas/functions/control-plane/src/aws/runners.ts
index 193c82d2e7..93b52e0a90 100644
--- a/lambdas/functions/control-plane/src/aws/runners.ts
+++ b/lambdas/functions/control-plane/src/aws/runners.ts
@@ -201,9 +201,26 @@ async function processFleetResult(
 
   const failedCount = countScaleErrors(errors, scaleErrors);
   if (failedCount > 0) {
-    logger.warn('Create fleet failed, ScaleError will be thrown to trigger retry for ephemeral runners.');
+    if (instances.length > 0) {
+      logger.warn(
+        `Partial fleet success: ${instances.length}/${runnerParameters.numberOfRunners} instances created. ` +
+          `Returning partial results; unfulfilled requests remain for retry.`,
+        { data: fleet.Errors, created: instances.length, requested: runnerParameters.numberOfRunners },
+      );
+      return instances;
+    }
+    logger.warn('Create fleet failed with zero instances, ScaleError will be thrown to trigger retry.');
     logger.debug('Create fleet failed.', { data: fleet.Errors });
-    throw new ScaleError(failedCount);
+    throw new ScaleError(runnerParameters.numberOfRunners);
+  }
+
+  if (instances.length > 0) {
+    logger.warn(
+      `Partial fleet success: ${instances.length}/${runnerParameters.numberOfRunners} instances created. ` +
+        `Error not recognized as scaling error; returning partial results.`,
+      { data: fleet.Errors, created: instances.length, requested: runnerParameters.numberOfRunners },
+    );
+    return instances;
   }
 
   logger.warn('Create fleet failed, error not recognized as scaling error.', { data: fleet.Errors });