I've had only 2 successful guinea moms. One was my first, when we knew nothing of what we were doing! She hatched 16 keets out in the brush. We lured them all into a pen just before a cold snap. She was the best mom. Biggest surprise for me was that the males were equally attentive. Her preferred mate stayed in the pen with her and the keets. "Uncle Ernie" would keet-sit once we let the little ones out to range. Years later another mom went broody all on her own in the pen. I took a photo and had a cross-stitch pattern made of it.
Since then I used banty cochin hens to incubate my guinea eggs. They can sit on 10-12 each and make really good foster moms. I've found that my chicken-raised guineas tend to stick closer to home - until the hormones kick in!