The Bass Trap corner positions are fine. However I recommend floor to ceiling ones. GIK have TriTraps and RealTraps now have a larger high performance one. DIY is easy enough. See SuperChunks at
studiotips - tips on studio design, acoustics, and wiring
The side ones are questionable. Take a look at where your modes will be on this
hunecke.de | Room Eigenmodes Calculator
Position your other traps where they matter most. This could be overhead, or at ceiling/wall corners.
DD