Question Fan place advice

[A4G]

Hey guys
look here at this simple case airflow

https://ibb.co/t2hjYX8

you can see there is 3 places for the front intake fans, but i will only place 2, where should i place them ?

 

[Lafong]

Any difference may well be within the margin of error, but there's no better way to find out than by experimentation....take a half hour of your time and find out.

You would then be the world's foremost authority on the topic given your particular circumstances. We don't know the finer points of your situation and can mostly just speculate.