Well... if we go down this path, then:
firstly: in the initial assessment, the Hydra will still lose...
secondly, and most importantly: we will start comparing different combat tactics... but here, we are comparing the raw strength of the units...
Sincerely.
The issue isn't about combat tactics... people are just saying that it loses almost every duel and is therefore weak... But if you give it higher stats, then with its abilities, the Hydra will be a walking terror on the map... that's why it was weakened with its stats, but its abilities were enhanced...