Super massive black holes and cosmic voids would cause a similar type of coordinated movement that would appear as expansion.

that is what you claim. i dispute the claim. in fact the claim is very certainly wrong (i'd have to ask you to support your claim).

furthermore i said:

How would a big bang look different than a big pull if the same region had super massive black holes and cosmic voids sprinkled throughout the same space?

that in turn is a valid question. you'll have to go into the math to see that they are different things. it may only appear similar as long as you are working on a purely qualitative level. as soon as you go into the quantitative level (the mathematical consequences of such a setup) you will find that they don't predict the same thing.

what do i mean qualtiative vs quantitiave:

qualitative: "couldn't the sun be just fire? both the sun and burning wood are warm. how do you tell the difference?"

quantitative: mathematical facts about wood burning and about fusion. conclusion: what we observe is not consistent with "a big piece of wood burning".

i don't see how a "cosmic void" would cause redshift at all

and

i don't see how some random black hole would cause redshift of light from all galaxies.

and you still didn't answer this.

it doesn't even fit qualitatively.