My experience with Wyandottes: I started with Wyandottes as my first chickens - 20 straight run: 10 gold and 10 silver, figured on 10 hens and 10 males, got 9 and 11. Kept the best looking gold & silver males and of course all the females. The gold male attacked people at 6 months, so he was out. The silver male was fine until the gold left, then he began attacking people. Tried for a year to make it work, but finally he had to go. Kept one of his sons that was out of a gold hen, so it's a Silver with gold "leakage" roo and he's a perfect gentleman. Some of the hens do have some aggression issues, but once they are settled in the pecking order they are fine. The ones lowest are the meanest to newcomers. Since the first chicks, I've only had chicks raised by hens in the flock - no introductions of strangers. Mine free range all day, so no space problems. I see your roosters are 8 months and the hens are a year old. I'm not sure that it's a breed problem or just getting to be part of the flock pecking order. All of mine eventually learned to like the new roo, even though some of them gave him a really hard time coming up. I think that's what has made him such a good roo. He had to earn his respect, he never had the opportunity to demand it. For you, 2 teenage cockerels to 5 pullets is a bit of pressure on the girls and could make them more cross toward them. I now have a total of 16 hens/pullets to the one rooster and am finally seeing things calm down. In my short years of having chickens they have taught me so much just by observation. #1 is that Pecking Order is Always A Thing. Elders always rule the pullets and cockerels. When the cockerel is rooster age, they will usually / eventually win over the hens that use to peck them down, but it's harder to win them over than the pullets younger than him. When the pullets become hens, there is yet another shift with the hen pecking order.
So many posters here have years and years of experience and I just have 3 years, so I'd look for more answers than what I have. The SLW breed - I have hatchery stock - is mixed. I have a couple of very very personable ones, so much so that one has a free pass for life... and a couple that were so aggressive and harsh I decided to expand to other breeds and even sent one to the freezer for being impossibly aggressive to the new pullets raised in the flock. Living and learning and loving it. Sorry I got so long winded on this post!!!