A sideline on Mason Adler: One of his problems is that while there's an obvious synergy between his two abilities, this can be short-circuited by your opponent simply leaving the mark out of the defending posse.Even if you're targeting my strongest shooter (which will often but not always be the case), it can still be worth it for me to use a backup shooter instead if that limits Mason to a 5 Draw.
I kinda feel like the key to a Mason-centric deck is (similarly to Jonah's Alliance) is to focus on one of the two abilities and treat the other as an optional extra.
Either
A) you build for him to run his solo job, with Sidekicks and other casualty-soaks, plus alternative stud-makers (Bowie Knives, Bad Company, etc...) so that his built-in studifying is just one of several options for this
or
B) you build for him to go on regular jobs/callouts where he makes himself a Stud (which both gives you more control over who you're fighting, especially if you're using the FMB home, and also lets you combine him with grit-manipulation like Black Owl and Rosenbaum's Golem), and just treat the job as something he does once in a while if the top opponent is particularly exposed.