It's not necessary to top outdoor plants at all, with most strains there is no advantage regarding yield.
There are exceptions but with most strains when grown outdoor you are simply changing from producing fewer larger colas, to a greater number of smaller colas, the yield in the end is unchanged.
It is sometimes advantageous to top and or train to take better advantage of your growing space. But, it's not like indoors where you are trying to get all your plants to be the same height, or spread them out for better light distribution. The sun is far less directional, the sun moves around and its light is more evenly dispersed, which means there is no compelling reason to top outdoors unless it is to allow plants to fit a space better.
That's my opinion anyway.
Your plants are looking good.