Actually, I want to go off this.
This theory can probably be destroyed with an easy-to-find quote. But then, the person who said it might not have the power of lateral thinking...
Point 1: It is clear that all casters can lead stacks and do other warlord-type things, just to a lower scale. So, are we sure that Warlords can't also do magic, just to a lower scale. Perhaps they have no specialty and can only cast from items or scrolls. Or possibly, their warlord ability is a spell school of it's own.
Point 2: Given that Parson, Judy, and Charlie are all originally from stupid world. What if they are ALL Warlords and not casters. Meaning that Charlie has no more innate casting ability than Parson, Judy, or theoretically Jillian (all the other Warlords).
Charlie, like the Wizard of Oz, came in and pulled off a bunch of illusions making people think he was a Carnymancer, when really he just had the Signamancy of a Carnymancer, again, like the Wizard of Oz.
However, much like parson has a Mathamancy bracer to make him ACT like a caster, Charlie has the Arkendish (and possibly other tools) that gave him all the power of a caster.
Back to the Topic: Given points 1 and 2, Stanley might just be able to do a link-up.
- Even just given the idea that Charlie isn't innately a caster, but his Arkentool has made him one. This should mean that link-ups are feasible through the Arkentools.