I have a treasured weeding tool: a WW I spike bayonet. The gradual taper makes it easy to push deeply in to heavy or rocky soil.
Something about the dogleg mounting bracket and the circular cross section of the spike makes it easy to "swizzle" in a circle around the weedy root. Like coring an apple, but on a taper.
Sometimes I get a surprisingly long bare root, and sometimes I pull out a "cone" of clay around the root.
I also have some 69 cent used knives from Goodwill. They are narrower and longer than my trowels, as strong, much cheaper, stainless steel, and have better handles. I usually dull the edge and sometimes shape the tip into a Vee.