Technically, it would work; however, you might lose the properties that make each ink unique (ex: porous, non-porous, dye, pigment, waterproof, translucent, opaque etc etc)
Keep in mind also the types of pads you're re-inking. The pads are used to disburse the type of ink they are made for. Dye inks usually come on felt pads and pigment inks are usually on a sponge base.
Also-color matching wouldn't be exact.
Thats why I don't ever mix re-inkers and pads, but if these issues don't bother you, then go for it!