Can I ask what your goals are for the tank? This will help decide if the array will fit your needs. You have a good start, but it may need a little tweaking.
You mentioned that you are looking to replace 2 T5s, but don't state wattage. Also you haven't stated your tank dimentions. This info will help shape things.
Epic, thanks for the plug
Forgot about the goal. Not sure if I understand the question totally but as I mentioned earlier I want to replace the T5s. The lED should be able to support plant growth so I am looking at the combination of blue and white (no red...but let me know). I currently have about 3 WPG but as I read in multiple places they are not a good measure. I am not really sure what is a good measure for lights for plants.
I got the references of 100 PAR and 4 lumen/sq inch. Not sure which is better target but trying to calculate on the setup I sketched and see how close it can produce with these targets.
If I am correct lumen/sq in is probably not a good measure for light intensity helping photosynthesis so I tried to place the blue lights such that they cover maximum ground surface. That way along with intensity I am also ensuring that the right wavelenghts are hitting the surface. The rest of the places in the grid were filled up with white for visual impact only.
Let me know if that helps explain what I am trying to achieve.