I can honestly say I never thought of Signamancy that way, and while it makes terrifying sense it's also really depressing.
I mean, it makes sense with what happened to Digdoug and Ace. Both were basically treated as dirt or worse for not being they class of caster that the side wanted or having the wrong personality for their given caster class.
But there again, Ace, Holly Shortcake, and (buffalo) Bill are all radically
different as Dollomancers. Does this mean that diversity within the caster classes is confined to the stereotypes they're derived from in Stupidworld? Is it really so bad that fighting personal Signamancy is as challenging as fighting Fate?