You may want to contact your local State Extension Service by phone, ask questions about how well these types of grass survive in your local area. They may perform well or very poorly, enough so you would not want to plant them.
I do not have any sugar problems with our horses, so I had various plant choices. Too bad some had to get lined out because of our clay soil! They do not do well in clay according to my grass variety charts. Some of my favorite choices just were going to fare poorly, no use wasting my money on the seed. The Extension folks should be helpful to you concerning grass types in various soil types. There you should be able to locate their grazing experts to ask questions. Our local Extension is still closed for Covid, but you can call!
Another point I learned, is you may want to plant the various seed types one at a time because of their assorted seed sizes. Whether drilling or broadcasting, the big seeds can interfere with steady flow of mixed seeds exiting onto the ground. I broadcast seeded last year and had a lot of problems with holes getting clogged. When I talked to the drill rental people, they said it was best to spread one kind of seed, then adjust the settings for the next size seeds. This does require multiple trips across the field! But there should be a higher success rate in seed growth over the entire field, instead of one type seed spilling in spots here and there, not evenly spread. With the cost of seed, you want ALL those seeds germinating!
Not sure how you plan to prepare the ground for planting. Discing can work or tilling up the dirt. Tilling well, does seem to tear up the previous ground cover well for the new seeds. A minus is needing to rest the field a longer time so the seeds can get established well. On clay that can take awhile. Have not used a drill before, but plan to try seeding with one in an established hay field this spring. We hope to thicken the grass stand
With the occasional foal here, I do not plant fescues. I get volunteer clover blowing in on the wind, never purchased. I do keep it mowed to prevent the slobbers. Seems quite immune to being killed off! You want to buy good seed, perrenial seeds not annuals, so read lables carefully…