I just saw this post. Yes, my four guineas, who were raised in the coop with the chickens in a nursery section from 4 weeks old, were very very tame. They lived peacefully with the chickens for months. I loved them-two males, two females. When they were close to laying age, those terrible "teen years", my alpha male suddenly got it into his head that one particular RIR hen had to die. He attacked her constantly, then the other RIR's, then the other three guineas were helping in the attack. I got Hawkeye, my big Barred Rock rooster during the time I had my guineas on lockdown in their own separate coop. When released, my male Dodger made these runs at Hawkeye. The rooster could handle Dodger, but he couldn't handle being attacked from four different sides, being bodyslammed and run into the woods.
The writing was on the wall. They had to be rehomed. A BYC member in Asheville, NC, with a farm bought them and they were doing very well. Dodger met up with birds bigger and way tougher than he was-geese, turkeys, etc. I miss him so much and may have guineas again, but they will be hatched here by a broody hen. Don't know if that will change anything because they are what they are and nothing like chickens, but it may be worth a try.
Sorry about your problems. I love guineas.