When upgrading my 2009 27" iMac from 8 GB (2 GBx4) to 12 GB should I put the larger modules first/"Top"?

When upgrading my 2009 27" iMac from 8 GB (2 GBx4) to 12 GB should I put the larger modules first/"Top"? I've heard that you should always upgrade with larger modules first (closer to the display screen) and smaller last. So in my case: just remove the first pair of 2x2GB and replace it with 2x4GB leaving the back 2x2GB there, giving 12 GB.

Is this the best way to do this?