The legendary affix is a separate multiplier. The normal skill affix is additive with other normal affixes of the same type, meaning it’s added to them to form another multiplier.
If you don’t have any normal HA affixes on other pieces, quiver 1 has total multiplier of 6.34 * 1.15 = 7.291. However if your pants and belt have 15% HA damage as well, quiver 1 is 6.34 * 1.45 = 9.193 and quiver 2 is 6.61 * 1.3 = 8.593. Quiver 1 is better.
Multiplicative and additive modifiers can get confusing a bit but this should help: