I'm very interested in this also. I've read things that made me say no to guineas and then read things that made me change my mind, and then back again! So confusing.
This article really got me thinking again...
https://homesteading.com/raising-guineas/
So, if I were to be accepting of the fact that I will lose my Guinea flock to predators it may be something worth considering.
Yes, that sounds horrifying, but let me give my situation. I live on an acre+ surrounded by woods. Ticks are a given. Ticks are dangerous. My 47 year old daughter who lives with me is permently disabled from tick borne diseases. She has neurological damage and is unable to do many daily things including driving. I have my chickens but can't free range them due to hawks, owls, etc so they are getting a 10x30 ft run.
I do have a lot of questions. If my dogs are outside on their chain runs will guineas attack them or keep their distance? I'm in NJ with cold snowy winters with the occasional obligatory ice storm. If I had 10 guineas what kind and how big of a coop would I need? If I can't raise them through the temperature changes that keets need will it be ok to purchase young ones at the point where they can be outdoors?
I'm positive I'll have other questions. Maybe my post here will help OP in some way. We both seem to be on the same "first page".