You're still wrong. The ML-20 always fires less, it just isn't as bad as it was before. The ML-20 always fires 9 now instead of starting at 8. The LEFH fires 10. The last test I did was several patches ago so it wouldn't be quite as bad on an artillery duel, but all the other points remain the same. The LEFH vets faster, particularly if you can set it up within range of the USF base. Also, nobody builds arty to counter other arty. Arty is at best a soft counter to other arty so talking about an arty duel is just a red herring.
As for your comment An 80% dominance for either side out of 10 trials isn't much more unlikely than getting the expected 50/50 outcome., all you did was tell everyone that you've never taken a statistics class. Binomial distributions are covered in the first couple weeks. The probability of 80% for one side is 4.4% versus 24.6% for a 50/50 split. Those two numbers really aren't about the same.
Ml 20 has the same XP value as LeFH 105 and is one of best counter of OKW truck which in general is easier to get in range than USF base.
Generally speaking soviet entities has lesser XP value than axis ones so I can;t say that can agree that Lefh vet faster.