The toughest abort (B744) is on a wet runway below 80 knots, and it is vital that the throttles be closed immediately, and reverse idle selected (Sometimes you can do it without reverse but it stabilises the airplane if it is used). Therefore the captain must have the throttles from the get-go.
Suggest that when the FO pushes TOGA he lifts his hand and the captain takes the throttles at that point. Waiting until 80 knots is risky.