Mega man can break a shield using jump cancelled metal blades into the ground. In my experience, it's reasonably easier than doing Fox's multiple jump cancelled shines in place from Melee, but not by much.
Here's a video example at 2:30
The only problem I can imagine is that since Mega Man has to move forward in order for his sliding toss to hit the opponent, if you've got them against a ledge, they may get pushed off if they're stuck in shield, leading them to safety. Or maybe the movement would eventually force mega man to move past the target. I don't have firsthand experience to know if this is the case.