No need to put out the Capital Letter. I now assume that you expect Cabinet's members to be competent at the fields they have been assigned the head of.
I don't have that confidence. Mainly because of the occasional minister shuffling that happened in France, my birth country, in the last 20 years or so. I'm not sure how it exactly works in other governments, but I expect that the same principles applies: minister/members of the Cabinet have technical advisers on the specific field they lead, they just have the final word. Otherwise, they show up on camera when a significant event about their respective field happens, and that's pretty much it. In that regard, the ministers/Cabinet is just a Public Relations token with limited effective powers. And the current Canadian Cabinet is off the chart PR-wise.
Now, if you would pick people whose technical skills you think are best-suited for a specific field, remember that most of his time will be spent speaking to reporters, cutting ribbons and shaking hands, in other words not working in their field of expertise. That's why doing gender-based discrimination when picking Cabinet members doesn't have any impact on the technical effectiveness of the Cabinet, because the people actually providing actionable advice will be the same low-exposure individuals regardless of the Cabinet member themself.
The biggest feat of the current Cabinet is that it gives a powerful signal that they are trying to promote women's rights and equality while not hampering the actual government function itself.
Of course if you don't believe in women's rights and equality, you're left with the skills argument, which is pretty weak by itself: even with an unbalanced gender ratio, Cabinet members/ministers aren't primarily chosen for their technical expertise anyway, but for their closeness to the PM/president and to fulfill campaign promises/reward loyal lieutenants.