I don't mind them being aggressive as I would primarily be getting them for protection so I think aggressiveness might help.
You mean people aggressive? Guess it's not a problem as long as you don't have visitors that it might attack (friends or family's kids for example). While you may be comfortable warding off an aggressive roo, there are some liability concerns if it goes after other people.
Is it better to just get a dog at that point that does well with chickens?
If predator protection is your main concern but you still want to free range, then a well trained dog (or dogs) is probably your best bet.
That said, do you have the time to train a dog with your schedule and a baby on the way? It can take up to 2 years to train a LSG to be reliable with a flock. You'd also have to train the dog to know the boundaries of the property as some breeds have a penchant for wandering.