Back Yard Birds,
looked up my old post and you have to look at this page I was directed to...
https://www.backyardchickens.com/t/263053/miracle-hello-guinea-chicken-crossbreed
I think it is a must see and proves yes, they can cross mingle!
Yes, it is possible.
I had asked a similar question not long ago on the chicken forum and was told it is very possible
for the two to have 'guinea-chicks' but those babies would not be able to have babies.