"Hey XXX,and YYY, do you have time for a discussion tomorrow at lunch? I noticed some things that make me think the company could benefit from you two swapping some responsibilities. I've noticed XXX struggles to aaa,for example aaa1, aaa2 and at aaa3, and at aaa4 YYY seemed to feel very comfortable doing aaa despite having less experienced, and conversely I think XXX's experience might be better suited for bbb, because of my experience at CCCC. Happy to share more of my thoughts and get your own opionion on this at lunch"
I actually fail to see how you can respectfully tell someone you think they should swap roles and be sexist. Sure, if your whole argument is that "XXX isn't coming of agressive enough to survive in this boys game" then you might be accused of sexism...for some reason