as long as air intake is close to air venting, all should be good, which can be difficult with different sized fans. but I can't see how more fans where ever you can shove them wouldn't help in your situation, more air flow, more heat vented. if you have some spare fans from another case handy, it's sure worth testing. quite understandable. in the end it's what you like that matters. are all the fans connected to the mobo to control? might want to check your BIOS fan curves to see what tempt they start ramping at when idle.