refactor(query engine): balance NewNMergedProducers tree

[forshev]

Description

balance NewNMergedProducers tree

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.69%. Comparing base (60903ae) to head (32255fa).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #526      +/-   ##
==========================================
- Coverage   75.77%   75.69%   -0.09%     
==========================================
  Files         250      250              
  Lines       19072    19075       +3     
==========================================
- Hits        14451    14438      -13     
- Misses       4621     4637      +16     

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