Cables are much more versatile. You can use the leverage any way you want. Standing further, standing closer, off to the side. Much more exact contractions this way. With dumbbells theres only a short moment where your actually lifting the weight. The rest is carried thru with momentum.
Also try static holds. Time that. Beat the time next week. Keep progressing. Consider it a form of strongman training
Also try static holds. Time that. Beat the time next week. Keep progressing. Consider it a form of strongman training