Better...than...
And kids who got piano lessons were also better at telling apart two similar-sounding Mandarin words, which contained different consonants, than were students who got extra reading training, or who went through regular kindergarten.
In this sentence, could the second "were" be deleted? If not, why?
Source:
https://www.scientificamerican.com/podcast/episode/piano-lessons-tune-up-language-skills/