No, math favors hunting off-wagon if there are two scum or if there are three - as long as you assume not all scum wagon'd together on the mislynch. I think that's a reasonable assumption.
I used basic math to narrow down my hunting grounds to my best odds (either 25% or 50%, depending on variables VP and I just discussed).
Those percentages are worst-case scenarios assuming we lynch randomly, however, which we are not going to do. Here's why I chose Gamma:
Mafia is a game of uninformed majority vs informed minority.
The scum know who is town and who is not.
Am I suggesting we lynch everyone who has accurate reads? No! Sometimes our reads are accurate because our reasons are good.
Scum will know who the townies are, but they can't just SAY "I'm scum so I know NPOM is town." So they have to make up reasons.
Gamma is scum because he knew NPOM was town (he was right!), but his reason for believing this was wrong (NPOM refuted it himself, and Gamma has since admitted it was wrong).
Gamma is scum because Gamma distanced himself from the mislynch by giving reads that were
right for the wrong reasons.