Friedman was a statistician and Hayek a philosopher and historian.
Hayek explored every field and came to the conclusion that we were having the wrong discussion: the question is simply rule of law under the common law of tort versus discretionary rule of any other kind. Friedman proposed means of producing commons by market means. These works are largely compatible. What’s incompatible is holding a discussion of capitalism vs socialism rather than what they REQUIRE: rule of law vs rule by discretion (not rule of law).

https://www.quora.com/What-is-the-difference-in-thinking-between-Milton-Friedman-and-Friedrich-Hayek