Are we talking about the containment field Adam created to hold the residual spirit of the Shaper of Worlds? The problem with the Shaper is that it always had raw power, being an emergent Cosmic Cube, but it lacked imagination. One day I'll tell you a story about how I played a trick on one of the strongest players on my old college football team using a simple finger trap. He was strong enough to lift the front end of small car, but couldn't figure out how to free his fingers. That's how I see Adam and the field that he created to contain the Shaper of World's ghost. If I recall correctly, that force field imposed a bit of a strain on Adam.
More to my point, Adam's force field feat was diminished by Anti-Man, who effortlessly imprisoned both Adam and Monica in a force field that neither could escape. When a man who has Adam's exact same powers -- but far less intelligence -- creates a field that Adam can't remedy, something is clearly wrong in our estimation of Adam's rung on the ladder.