Please don't do this. The class doesn't need handholding. I main AST, I love the class and plan to raid with it. But. AST's buffing abilities are already more powerful than most players seem to realize, for one reason...Arcana and Royal Road cards can now be discarded via an action.
Sleeve Draw lets you roll the dice for extra cards, ie more chances at the holy grail AoE Balance. Sleeve Draw can result in back-to-back AoEs. I've accidentally overwritten my own AoE Balance with...another AoE Balance!
If you don't set up ahead of time you can end up with a bad RR. So RR again or deal with it. Sometimes I go for an extra buff, get bad cards, and everyone gets Spire in the stocking stuffers. That should be the price of Sleeve Draw.
AST has the tools to overwrite bad RRs already. AST cards should require using a little foresight or quick thinking--this change would just make the class braindead, when it's already borderline OP.