Abobe Garamond Pro was created in 1989 by Robert Slimbach. Myriad Pro was created in 1992 by Slimbach as well. With being only 3 years apart and having the same originator, the two typefaces can be put together effortlessly.
The Adobe Garamond Pro was designed to mimic the 16th century French type with its precise form and delicate flow. It has various stroke thickness types. I feel as though this font type would be best friends with Times New Roman and would spend its days drinking tea and living an easy lifestyle in a cottage on the countryside. It seems like it would listen to classical music and be a little of a clean freak. Although it likes to stick to its clean, concise ways, it is very versatile in its use and can be playful, especially when in lowercase form.
Myriad Pro is full of open shapes, precise letter fit and clean proportions. It is comfortable and clear to read like Adobe Garamond Pro, but also can be creative and playful when needed. I think that Myriad Pro would also happily live in a cottage in the countryside. But instead of tea, it would sip on lemonade. It would be the artsy one in the relationship, whereas Adobe Garamond Pro would be more structured and logical. Myriad Pro would be clean and concise, but would travel by foot and switch off listening between Kenny G and Janelle Monet.
Neither typeface is too crazy. They are both relatively simple and structured. I believe that when Robert Slimbach designed these fonts, his main purpose was versatility, simplicity, and usability. I would use both of these fonts in many different pieces containing very different subject matter. They are simple enough that many styles can fit to them. I believe that these two fonts would definitely be happy together in their little countryside cottage.