When I was a kid, there was a B John Deere that pulled a LOT of large boulders out. All I needed was a chain. Use the bucket to expose a point on the rock so one could wrap a chain around it, then give'r the onion. My bucket was an old rockpicker with a toothed lift like this one:
You would bend or break the teeth messing with the rock, but they worked to get the dirt away from the edges.
As an 11 to 13 yr old...I rocked at removing what I thought were big rocks. Some probably weighed near a ton or two.