There are mechanisms to be sure, but the real way to do this, of course, is the MP KS that "Snappy Nappy" allows.
Which is the "Flight of the Eagle" KS with minis.
Which is why we're doin' it
.
None of these systems I've been poking at really do good FoW without another table or two. I was quite surprised to discover how quickly the cards get revealed in "Blucher". Honestly, I'm almost of the mind that they're not worth the bother.
Don't get me wrong, I really, really like a number of them (Blucher is presently at the top along side C&C which is an entirely different game), but FoW is something best sought in the arms of Von Reisswitz.