I tried doing that, the problem is getting it perfectly aligned with the player.
I have some really bad memories associated with aligning models with players...
I was rendering a .obj model as a sword and it was hard. I had to change a number than restart minecraft. Till I found the perfect match. It was a painstaking process that took a long time.
Then after I finished spending hours on trying to align it, I found out that in debugging mode, it will change it without you having to restart minecraft. So, just run it in debug mode and try looking for the perfect numbers.