A 50' x 50' aviary if sectioned off, could have 10 or 5 seperate runs, depending on how wide you make each run. You also need to consider one end having a covered sheltered area. You will also want to have a seperate enclosure(s) for quarantine/hospital enclosures because birds do get sick or injured and need to be separated from the healthy birds.
It is best not to mix different species of gamebirds in one enclosure. Yes, it can be done but unless your very experienced with those type enclosures and have a good knowledge of the different species behavior that will be kept in those enclosures, have strict biosecurity protocols in place, provide suitable habitat structure, etc, etc...its not likely to be a good experince for you nor your birds.
I've kept different species of all male pheasants in a community enclosure with no problems. I've also kept 2 different species of quail in 1 enclosure but in both cases, the enclosures were huge 100' x 100'. I've also had the same arrangements work or a period of years, then all of a sudden chaos broke out and a blood bath insued.
Ring necked pheasants, partridges and Guineas have very aggressive behavior towards other birds not of their own kind.
I raised my guineas "free range" so I have no experince with them in an enclosed environment.
@R2elk can better advise you on keeping guineas.
These have been a few of my experiences with mixed flock enclosures. Your experince may and probably will differ. What works for someone else may or may not work for you. Take the best ideas from others and apply them to your own arrangements. Good luck with your endeavors. HTH.