yes, you can do what you suggest and it'll work fine.

as long as you arrange them in a big square with the fans side by side like you suggest, like:

xx
xx

just do not stack them ontop of one another - this method would accomplish very little

and make sure your ducting/hole/whatever is large enough to accomodate pulling that much air through without the fans having to work too hard for it, otherwise you'll start losing CFMs.