The phrase "complementary skills" means having abilities that go well together and help each other, like two puzzle pieces fitting perfectly. Full definition
Put people with complementary skills together on a task, especially if they have not had cause to spend time together. (rismedia.com)
A business potentially can reach new heights when complementary skill sets are gathered under a partnership. (inc.com)
The bottom line: With the help of complementary skills spouses should make a formal retirement plan together and share their financial decisions. (personalmoneyservice.com)