Just a friendly suggestion.. don't put your friend letter in your file... it has no relevance to your file.. Its his luck he got Visa with same profile.. He never used anyone reference in his SOP... If you do this.. IRCC will take as you are blaming them of discrimination and can offend Visa Officer..
Try to justify.. i.e. relevancy and future prospect... may be learn from your friend SOP...take some expert advice...
It's not my friend's SOP. They have written letters in favour of my approval and how my previous job/education helped me during the program.