I think what you should do in the meantime is just watch your flock and see how your hens handle the rooster. Granted, everyone's immature, so mating isn't going to be pretty for a while, but since your birds free range I think your numbers could be fine. Your hens have plenty of opportunity to get away from the rooster, they're not cooped right up with him all the time. It's one of those things you can't say for sure what's going to happen, but try it and see. He could be a perfect rooster from the start, or he could be a psycho stalker rooster who constantly harasses one specific hen until she spends her days hiding from him and he spends his days perched over her hiding place waiting for her to come out. I've had both ends of that spectrum, fortunately way more on the good end, only one psycho stalker (he tasted delicious!).
If you're not familiar with how chickens mate, do a search on some of Ridgerunners older posts on the topic. He details things quite well. If, even after a period to account for immaturity, your hens are stressed by your rooster to the point it's causing them (or you) issues, then at that point re-assess your rooster's future.
