Why use 交货 in 我们可不可以把有些数量提前到三月交货？ 我们可不可以把有些数量提前到三月交货


Why do we use 交货 here? Can we do without it?
Consider this part of your sentence with 交货 (t: 交貨) omitted, its spot represented by the ___ below, this would be what it looks like, loosely translated:

subject:           predicate:
... some amounts   be rescheduled earlier for March ___


There are some terms or concepts in language that, although are not verbs themselves, have a commonly associated course of action understood by everybody. Only in such cases, it is possible a further specific verb, course of action ___ can be omitted. However,

Amounts:


is not normally understood as some kind of verb or some kind of action, for which you can then associate with a schedule clause
in this case, with no further context, there is no single "obvious" course of action to relate to amounts. For example amounts if talking about some physical goods or material resource, depending on what kind of goods or material resource, can have associated actions such as extraction, refinement, disposal, audit, inventory (taking), and yes, also delivery. Without further context there is no evidence that "delivery" is the correct interpretation


Example, omit action:



subject:               predicate
... the belly dancer   be rescheduled earlier for 7PM ___



As in Can the belly dancer be rescheduled earlier for 7PM ?
it is commonly understood that a belly dancer belly dances, that is a commonly associated course of action understood by everybody
thus you do not need the additional ___ to clarify for 7PM belly dancing
you would normally only specify the ___ action clarification, if the belly dancer were to do something other than the expected belly dancing


However in your posted example, without further context, since amounts does not necessarily have a commonly associated course of action delivery, of course you need to clarify and specify which of the possible action of amounts you intend to reschedule.

Image credit: http://www.picgifs.com/graphics/belly-dancing/graphics-belly-dancing-471150-794732/