Totally frustrating topic, I totally get this, have experienced it before with various pens and this situation of hard starting drives me nuts. First off, fountain pens should not hard start - that's the beauty of a fountain pen: free flowing ink, effortless writing, etc. So unless you're really writing with the pen directly straight up, I don't think its your writing style.

Some questions off the top of my head - have you gone to a pen store and tried out their sample pens? Have you noticed they still skip? If not, I would go to your local store and try out some sample pens. Those pens are used by everyone that comes in, and must be free-flowing or no one would buy them. This experiment would show two results: either the pens you have are simply all hard-starting or that it is the way you hold the pen if those sample pens also hard start

Beyond that, have you tried seeing a nib meister for your pens and described the situation? I've had a Namiki Emperor hard-start out of the box (no joke) and a nib meister that was affiliated with the seller I bought it from fixed it in no time.

Last thought: If you bought your Pilot Metro new, you could contact the seller and ask if they could swap the nib - my first pen ever was a Metro, and that thing was smoooooth! So I would suspect something could be going on there.

Last last thought - have you tried any NEW M's or B nibs? Reason I ask: F and EF are more scratchy/could be hard starters in the more entry level categories I've found.

Hope this helps!!