Is this possible? it gets quite annoying when I want a hero to cast a spell right after his Meteor Shower and he cancels it after 4 seconds to cast the new spell.
Just be on time with when it just finishes casting MS and hit your next spell you want them to do. All i do, I figure if i need them to spike something the way i want them to that badly then i'll just to pretend to play 2 chars at once with my Skill Bar and the Hero.
You can 'queue' up the next as soon as the hero starts casting as far as I know, that way, while the casting animation has started you can have the next skill ready.
Heroes can't truly cue a followup skill as we can since they are programmed to follow orders. They will interrupt their current action to follow whatever you have ordered them to do.