A person is commenting about his experience working with two well known writers:
あのニ人は創作能力で言えば日本で指折りのクリエイターだ
俺じゃ逆立ちしても出てこない知見ばかりだったよ
I have trouble understanding the 知見ばかりだった part. I guess 知見 refers to a person who watch and learn? What nuance does ばかりだった add? Also why it is in past tense?