Vintage Heroic Tokens is not the answer. This is.

D3P2K5

First of all, i have to say, the whole thing with vaulting characters was a bad idea. The majority of your player base agrees with this. The fix for this while maintaining the concept of being able to complete latest characters quickly is this:

Latest Legendary Tokens - feature the 12 latest 4* along with the 3 latest 5*
Classic Legendary Tokens - feature the rest of the 4* along with the rest of the 5*
Heroic Tokens - feature the latest 20 3* along with the 12 latest 4*
Elite Tokens - feature all 3*
PVP and non-Vault PVE Tokens - feature all 3* and all 4*

This should be simple to implement and will give the player base the most flexibility.