You've still managed to caveat it with a reference to other managers but I suppose it's the closest we're going to get.
To answer your question, given the choice I'd go with Gannon as he'd be more committed to it long-term than Rusk will be, in my opinion. If Rusk does well here, given his reputation amongst bigger clubs from his time at Brighton, he'll take a better job if it's offered.
That's not to suggest he's not 100% committed to the job whilst he's doing it, just that he'll have an eye on moving up the ladder; McGhee said as much when he joined.
I've said it a few times but Rusk won't see out his contract here, whether it goes well or not. If it goes well he'll move on to a job in a higher division; if it doesn't go well then he'll be sacked.