If the contents of a large storage chest are non-stackable items and there is a minecart with hoppers instead of hoppers underneath, the items will not be evenly distributed to all minecarts with hoppers.
如果大型儲物箱裡面的東西是無法堆疊的物品，並且下方連結漏斗礦車而非漏斗，會無法平均分配給所有漏斗礦車。
※The above English part is machine translated, please forgive me if there is any inaccuracy
※以上英文部分為機器翻譯，如有不準確敬請見諒
This is because hopper minecarts are entities, and the order in which entities get updated within a game tick is not randomized. If you use hoppers instead of hopper minecarts to move the items you will get a more even distribution over time because hopper update order is intentionally randomized.