Our male guineas used to mildly harass our roosters when we had them, no blood drawn.
Their attitude toward hens seems to depend on the rank of the hen in the hen group, whether the hen is older or younger (I think they remember the older hens as "bigger than them"), etc. No major issues though, just a little posturing and short chasing over treats or territory. Some hens will chase a guinea, too.
They are free range in the day and the coop is divided so they can't get at each other in a confined space at night. That probably helps.
Beautiful pic Southern Oaks!