Okay... Thanos is more powerful than Superman.
Superman would in no way shape or form be hurt by anything the Preds could chuck at him.
Thanos would absolutely annihilate the Preds! Every last one!
And if they all used their nuke-watches.... BOOM!
The smoke clears, no more Preds... and a slightly singed Thanos standing in the middle of a pile of ashes....