Mordin like many of the aliens in Mass Effect has alien proportions, So getting someone to match them is often impossible. You have to compromise with some things, but keep the spirit and keep them recognisable.
For example i'm slowly working on a Tali, and she has odd legs - extreme bent back calves - I have hypermobility but even i cant bend my knees back that far! So im compromising by adjusting the padding on her shin armour to enhance the weird curve.
When i saw the costume i instantly knew it was Mordin, even though you had to compromise with human proportions.