You're definitely right about that, it is redundant, but for example some people count a McDo hamburger as meat and cake as eggs.

I would do just fine with eggs, fish, dairy, and meat, as I have done during small periods of time out of laziness. But diet is not just the nutrition, it involves pleasure and has a social aspect too, among many other things, so for instance I find that walnuts pair really nicely with my scrambled eggs and give a satisfying crunch, and when it's strawberry season I'll support some local producers.

Here is my template: I ballpark 2 to 2.5 grams per kg of ideal/lean body weight from a distribution of eggs, fish, dairy (cheese + yogurt), and meat, sometimes it is less, sometimes it is more, I don't really care to track it precisely, and this adds up to roughly 25% of my energy intake. These foods themselves, along with some cooking fat/oil, are about 50/50 protein/fat in composition, so I'm also getting a bit more than 55% of energy from fat already. Finally, there is something like 20% of energy intake remaining, which comes from one thick slice of whole-grain rye bread, a handful of nuts, minimal seeds, vegetables about once or twice per week or so, some fruit like prunes or dates, a bit of dark chocolate, a bit of honey, etc.

No issues to report, except that I have to do at least a couple of hours of some activity per day, be it cycling, strength-training, walking, etc, otherwise I won't be tired enough to fall asleep easily.