So you think it won't be a problem to put 6 fans on the rads as OUT.
1 OUT at back of the PSU.

2 on top IN, blowing on mobo (cause I have MM horizon case).
1 back IN, blowing over mobo.
2 back IN, blowing under mobo, straight to the rads.

So will the case have enough IN take for the RADS to cool?