Hurray for Guineas!!! They are all I have and love!
Sorry you lost two. I would say keep'em locked up a lot longer than you would think... I know it is not ideal but that is my experience.
Make sure they have all they need and don't beat each other up but I find the longer they are confined, the more they love their home.
When I first got Guineas I did not know I needed a run. They were in the coop for several months while I was feverishly buidling their run since I loved them and did not want to lose a one.
I brought greenery inside and meal worms and made hiding places and nesting sites - all inside the coop and watched them every day for bullying and such while I was building out there.
It paid off in a weird way - at first they did not want to go out at all (not even into the connected run) and certainly no-one up and left. The coop is their home and their safe place. They are very much bonded to it. I can't even clean it without some of the watch duty guys alarming the flock to come back from the fields and see what is happening to their coop. Can be bothersome to have protesting Guineas between your feet as you try to shovel out wood chips, he he.
I never wanted them locked up that long, but in retrospect I am grateful that it happened that way. It was a good six months before they went out, and the first outings were under tight and constant supervision.
Now I can let them out and leave to go shopping and they will wait for me at dusk to get their treats and go back into the coop for the night. When someone does not come home, my heart sinks because chances are high that a predator got that one. A couple of times, I was so happy, I found the missing flock member on the other side of our 4' fence running back and forth, desperately trying to get back home. They seldom go over the fence now, but when they do, they may get stuck on the other side and not realize that they can fly over to get back. The only other time someone does not come home is when a hen has gone broody on an outside nest.
This year I caught Poppy making a nest in the woods where I can't reach her and she is not going out for 2 weeks now since she will be eaten if she starts sitting on that nest. She is unhappy but alive - and Herbie is confused but at least he will have her back soon, which would not be the case if she got eaten out there. He is hanging around the run, wondering why she won't come out to the fields with him. He is running around all sides, peeking over the barrier to see her. When they all go back in, he has her back for the night and they roost together.
Guienas often bond one-on-one for life - I hope you don't get some broken hearted birds missing their mates. That is why I don't buy or sell adults. Of course, there may be circumstances to make it necessary but adults pose more challenges and have greater potential for heart-ache, the birds' and yours.