I know we've talked about this before, but sometimes, I think we need to be reminded of this:
The mauraders made a map that could see through the invisibility cloak.
I mean, okay, so if we take all of the things we hear about the hallows, then they are not actually these invincible weapons. In fact, the story of death really seems to be somewhat exaggerated. If the wand was really that powerful, then in a straight on duel, then no other wand should be able to defeat it, and no one else would ever conquer the wand except by sneaky means. If the cloak was that strong, maps made by teenagers should not be able to see through it, or it wouldn't be easy to touched, or the person shouldn't be able to be hit by spells while wearing it. So at best, they are very good at a specific thing, and maybe that's something that in modern wizarding world has been lost in time. Though regardless, they are very strong magical artifacts, but are not actually something that's infallible all put together. Though, the story of the Hallows itself seems to say so much.
However, even with that in mind, this is a strong magical artifact and it would not be easy to spell this map to identify people under it.
These boys were geniuses, and I feel that's underappreciated most of the time. Maybe it was just a good team where all their skills built off each other, but it still seems that if they hadn't been broken apart, they would be ruling half the wizarding world themselves.
