In the counting captures lesson, toward the end, the lesson argues it is somehow better to sacrifice a bishop and a rook to capture a pawn, bishop and rook rather than sacrifice a bishop and knight to capture a pawn, bishop and rook. I don’t see how that adds up mathematically. In the former scénario white is +9 to +8 while in the latter scénario white is +9 to +6. Is there an error in how the lesson is presented or am I missing something?