Heat oven to 325°F. Season beef with salt and pepper; brown in oil in a small Dutch oven 3 minutes per side.
Add broth, water, onion, garlic, and Worcestershire. Cover; braise 3 to 3 1/2 hours until beef shreds easily. Check once, spooning a little measured broth from pot over exposed meat.
Shred meat; drain thoroughly, reserving cooking liquid. Strain and skim liquid; keep hot for dipping. Increase oven to 350°F.
Split connected rolls horizontally; put bottoms in a parchment-lined 9-by-13-inch pan. Layer half the provolone, drained beef, and remaining provolone. Replace tops.
Mix butter and onion powder; brush over rolls. Cover with foil; bake 15 minutes. Uncover; bake 8 to 10 minutes until center reaches 165°F.
Rest 5 minutes; cut into 12 sliders. Serve with hot strained broth for dipping.