Like main-cogg said, you’re looking for a face mill or shell mill if you want multiple cutting edges in one tool. The fly cutters I’ve seen only have one cutting edge, either ground or an insert. Some use a ground tool, some use an insert. I’m no expert, but one advantage of a fly cutter is the diameter of the cut can be adjusted, while a face mill’s diameter is what it is. That’s not critical for narrow work pieces but can be advantageous for wide ones. Hopefully, someone with face mill experience will chime in. You can also search the forum for face mills and find previous threads that might answer your questions.
Tom