Your idea of mafia theory is probably different from mine, exlight. To me, the greatest source of information is re-analyzing old wagons with new flips. That means that every time anybody dies, the best thing to do is to look at every previous lynch and look at how the wagon's developed while keeping in mind the alignments that are now known. This means I intend to return to the D1 wagon every time anybody dies.
Analyzing a wagon also doesn't mean analyzing the person the wagon built on. For example, if FG dies and flips scum, that makes whoever cast the decisive vote to switch the wagon from FG to Allmight look bad. I think it was either deku or sun, but I'd have to check. In any case, analyzing the wagons with new information provides information on every single player (in varying amounts), not just on the wagon leaders. You can think that both FG and silver are town and still gain information from analyzing the wagon.
I don't see what you have to gain by vigging someone you think is town.