While it's true that a large part of grading is objective (locating print defects, staining, surface wrinkles, measuring centering, etc.), the other component of grading is somewhat subjective
Each half of the expansion has its own personality, with Black Bolt centered around Zekrom, Kyurem, and Genesect, while White Flare features Reshiram, Keldeo, and Hydreigon
For example, you could exile four cards illustrated by Zoltan Boros and one card illustrated by Zoltan Boros & Gabor Szikszai
6th place: Venusaur (B2 18) #18 In 6th place on our top 10 list from Base Set 2 is Venusaur (B2 18)
It specializes in dealing damage while returning the opponent's cards to the hand/deck
Its fine in the context of this deck