I do think a good rooster really helps with daytime flock protection. Thing is, not all roosters are good roosters. In fact, a lot of them are not. Your current rooster is one of those. Most of us have kept a rotten rooster too long the first time. But look around, roosters are plentiful, and anyone who hatches, generally would love to give some away.
What you really need is a rooster that someone has, that should have been culled, but was not cause he is so nice. Ask around, 4-H groups or poultry groups. What is best is a rooster that is about a year old, that has been raised in a multi-generational flock under a good rooster in similar geographic and predators to your own situation.
Roosters should be the first bird to see you, when you enter the area. When out and about, he should have his head up frequently, checking things out. He should keep his girls together, and should escort them to lay. He should wing dance and tidbit.
My daytime predation drops dramatically with a good rooster, and while I have read that a hen will step up, mine never have. When mine 'free range' they are out in pastures of hundreds of acres, not just out in the yard.
However, I am very rural, and we have a lot of predators so I do not free range all of the time. I mix it up, somedays all day, some days parts of the day, and sometimes not at all. If you have serious predator, you need the option to going into lockdown. Once a predator finds you, they will be back, and bring others.
Mrs K