You described some strange arrangement on some aeroplanes whereby the engine would stop on the rollout if the pilot left the throttle closed. Properly set up Chippies don't do that.
You
don't need your hand on the throttle if you are applying brake to slow down - a point I've made several times and which led me (and Janie) to ask why anyone would.
You'd want to apply power if you were about to hit something..???