Here's what everyone forgets. Instead of looking at the individual talent, look at the preference for how each wants to be coached. RG 3 wants to be in a pistol, zone read offense. That requires big receivers on the outside to help block.
Alfred Morris wants to be in a one-cut feature the back offense.
DeSean wants NO part of blocking. He is best in Chip Kelly's offense that spreads the ball all over the field.
RG 3 and DeSean may be great talents but they are NO GOOD for each other.
However, if Kirk Cousins was QB, then I'd be afraid. He's a pocket QB who uses the weapons around him. RG 3 thinks he is the only weapon needed.