The SS should cover 2nd and on my travel team, the left fielder covers 3rd, on my school ball team if the 3rd baseman didnt field the bunt they would get back to 3rd, if they did field the bunt, our pitcher would cover third
I would be hesitant to have my C cover 3b, especially with a real good bunting team in the heat. I'd have my speed girls start pounding it to the 3b side to make the catcher have to run back and forth all day long.
Catcher covers 3rd if 3b fields ball, if not 3b peels back to base . We would never use a OF to cover a base and try not to have the pitcher either.