Too much air exchange?

Is there such a thing?
I'm growing in a 3' x 3' x 6' tent and purchased a 400+ (460 I think) cfm fan with a speed adjustment knob... the adjustment broke and only works at full speed...
That is a lot of air exchange!
Is that a problem?
I will have two 6" clip on fans blowing across five (HOPEULLY 5 FEMALES!) tops and two 8" fans blowing from the bottom...
There are two 4" x 12" passive vents at the bottom that I plan on using, but there are also two 4" diameter cutouts I can turn into vents...
Any suggestions/input? (minus buying another adjustment control!)

I have not ever heard of to much air exchange in less you are using c02, but maybe this is why mother nature stop blowing so much sometimes lol

Its not a problem to have lots of air exchange. You have gone a little overboard on the fans blowing across the canopy though. But you can always turn some of them off or down.

Too much air exchange is only bad if it lowers the humidity too much. If it makes the air too dry, then no it's not good. I actually switched from 400w hps and 600w hps that I used in 3x3 area's, also 4x4 areas, to 315w cmh, so the temps and humidity would be better. They are much better, like perfect. Rh is bang on and I can choose my temps with adequate air exchange.

What is the humidity in your growing area?

I would remove 3 of the fans you have in there and just have one blowing across the top. The big fan will likely suck in the sides of your tent even with the vents open but it shouldn't be an issue.