diff --git a/internal/querycoordv2/balance/channel_level_score_balancer_test.go b/internal/querycoordv2/balance/channel_level_score_balancer_test.go
index 2188940ec7..40e1886afb 100644
--- a/internal/querycoordv2/balance/channel_level_score_balancer_test.go
+++ b/internal/querycoordv2/balance/channel_level_score_balancer_test.go
@@ -245,7 +245,7 @@ func (suite *ChannelLevelScoreBalancerTestSuite) TestAssignSegment() {
 			for i := range c.collectionIDs {
 				plans := balancer.AssignSegment(ctx, c.collectionIDs[i], c.assignments[i], c.nodes, false)
 				if c.unstableAssignment {
-					suite.Equal(len(plans), len(c.expectPlans[i]))
+					assertSegmentPlanNumAndTargetNodeMatch(&suite.Suite, c.expectPlans[i], plans)
 				} else {
 					assertSegmentAssignPlanElementMatch(&suite.Suite, c.expectPlans[i], plans)
 				}
diff --git a/internal/querycoordv2/balance/rowcount_based_balancer_test.go b/internal/querycoordv2/balance/rowcount_based_balancer_test.go
index 1c7ce6ea35..39c23f8211 100644
--- a/internal/querycoordv2/balance/rowcount_based_balancer_test.go
+++ b/internal/querycoordv2/balance/rowcount_based_balancer_test.go
@@ -1258,6 +1258,31 @@ func assertSegmentAssignPlanElementMatch(suite *suite.Suite, left []SegmentAssig
 	}
 }
 
+// assertSegmentPlanNumAndTargetNodeMatch checks that:
+// 1. The number of plans matches the expected count
+// 2. Each plan's target node is in the expected target nodes set (extracted from expectPlans)
+// 3. The number of unique target nodes matches between expected and actual plans
+func assertSegmentPlanNumAndTargetNodeMatch(suite *suite.Suite, expectPlans []SegmentAssignPlan, plans []SegmentAssignPlan) {
+	suite.Len(plans, len(expectPlans))
+
+	// Extract expected target nodes from expectPlans
+	expectedSet := make(map[int64]struct{})
+	for _, p := range expectPlans {
+		expectedSet[p.To] = struct{}{}
+	}
+
+	// Extract actual target nodes from plans
+	actualSet := make(map[int64]struct{})
+	for _, plan := range plans {
+		_, ok := expectedSet[plan.To]
+		suite.True(ok, "target node %d not in expected set", plan.To)
+		actualSet[plan.To] = struct{}{}
+	}
+
+	// Check that the number of unique target nodes matches
+	suite.Len(actualSet, len(expectedSet), "number of unique target nodes mismatch: expected %d, got %d", len(expectedSet), len(actualSet))
+}
+
 // remove it after resource group enhancement.
 func assertChannelAssignPlanElementMatch(suite *suite.Suite, left []ChannelAssignPlan, right []ChannelAssignPlan, subset ...bool) {
 	type comparablePlan struct {
@@ -1300,3 +1325,28 @@ func assertChannelAssignPlanElementMatch(suite *suite.Suite, left []ChannelAssig
 		suite.ElementsMatch(leftPlan, rightPlan)
 	}
 }
+
+// assertChannelPlanNumAndTargetNodeMatch checks that:
+// 1. The number of plans matches the expected count
+// 2. Each plan's target node is in the expected target nodes set (extracted from expectPlans)
+// 3. The number of unique target nodes matches between expected and actual plans
+func assertChannelPlanNumAndTargetNodeMatch(suite *suite.Suite, expectPlans []ChannelAssignPlan, plans []ChannelAssignPlan) {
+	suite.Len(plans, len(expectPlans))
+
+	// Extract expected target nodes from expectPlans
+	expectedSet := make(map[int64]struct{})
+	for _, p := range expectPlans {
+		expectedSet[p.To] = struct{}{}
+	}
+
+	// Extract actual target nodes from plans
+	actualSet := make(map[int64]struct{})
+	for _, plan := range plans {
+		_, ok := expectedSet[plan.To]
+		suite.True(ok, "target node %d not in expected set", plan.To)
+		actualSet[plan.To] = struct{}{}
+	}
+
+	// Check that the number of unique target nodes matches
+	suite.Len(actualSet, len(expectedSet), "number of unique target nodes mismatch: expected %d, got %d", len(expectedSet), len(actualSet))
+}
diff --git a/internal/querycoordv2/balance/score_based_balancer_test.go b/internal/querycoordv2/balance/score_based_balancer_test.go
index 470603d67b..b265ba9096 100644
--- a/internal/querycoordv2/balance/score_based_balancer_test.go
+++ b/internal/querycoordv2/balance/score_based_balancer_test.go
@@ -282,7 +282,7 @@ func (suite *ScoreBasedBalancerTestSuite) TestAssignSegment() {
 			for i := range c.collectionIDs {
 				plans := balancer.AssignSegment(ctx, c.collectionIDs[i], c.assignments[i], c.nodes, false)
 				if c.unstableAssignment {
-					suite.Len(plans, len(c.expectPlans[i]))
+					assertSegmentPlanNumAndTargetNodeMatch(&suite.Suite, c.expectPlans[i], plans)
 				} else {
 					assertSegmentAssignPlanElementMatch(&suite.Suite, c.expectPlans[i], plans)
 				}
@@ -1699,8 +1699,9 @@ func (suite *ScoreBasedBalancerTestSuite) TestAssignChannel() {
 				{CollectionID: 1, ChannelName: "channel1"},
 				{CollectionID: 1, ChannelName: "channel2"},
 			},
-			states:        []session.State{session.NodeStateNormal, session.NodeStateNormal, session.NodeStateNormal},
-			distributions: map[int64][]*meta.DmChannel{},
+			states:             []session.State{session.NodeStateNormal, session.NodeStateNormal, session.NodeStateNormal},
+			distributions:      map[int64][]*meta.DmChannel{},
+			unstableAssignment: true,
 			expectPlans: []ChannelAssignPlan{
 				{Channel: &meta.DmChannel{VchannelInfo: &datapb.VchannelInfo{CollectionID: 1, ChannelName: "channel1"}}, From: -1, To: 2},
 				{Channel: &meta.DmChannel{VchannelInfo: &datapb.VchannelInfo{CollectionID: 1, ChannelName: "channel2"}}, From: -1, To: 3},
@@ -1771,7 +1772,7 @@ func (suite *ScoreBasedBalancerTestSuite) TestAssignChannel() {
 			// Test channel assignment
 			plans := balancer.AssignChannel(ctx, c.collectionID, dmChannels, c.nodes, true)
 			if c.unstableAssignment {
-				suite.Len(plans, len(c.expectPlans))
+				assertChannelPlanNumAndTargetNodeMatch(&suite.Suite, c.expectPlans, plans)
 			} else {
 				assertChannelAssignPlanElementMatch(&suite.Suite, c.expectPlans, plans)
 			}