Well whips would certanly be one of the weapons to get a degree of shield bypass, but probably wont have a great chance to grab a target(whips aren't really that flexible)
Eh, depends on the whip. Some are stiffer than others, and the more flexible ones can grab--especially if specifically designed to do so. But the more flexible the whip is, the lower its ability to transfer the energy of each stroke into harming the victim. Then again, since the
worst damage a whip strike can do is leave a welt or a skin-deep cut (and that's only when the victim is wearing
no armor at all), it likely would be best to use whips as an "entangle-only" supporting weapon, like nets or bolas.
Fun Fact #1: Whips can be used with great accuracy--there are tales of Roman charioteers who could kill a fly on the wall on the other side of a room. But when a whip is cracked at a specific target like this, the force travels in a straight line, & there would be no potential for shield bypass or wraparound.
scourges can't grab
You must not have seen the nastier types of scourges. From your own link, "Hard material can be affixed to multiple thongs to give a flesh-tearing "bite". A scourge with these additions is called a scorpion." Both scourges and whips are sometimes given metal tips, and some scourges were even tipped with barbed fishhooks. In a combat situation, these could certainly grab skin (though the victim could fight the pull, which with enough strength would rip the hooks out) and chain mail.
flails would have limited shield bypass and no grab.
Again, it depends on the design of the flail; a shorter chain means less power from centrifugal force (& less wraparound potential), but more accuracy. It might be interesting to randomize flail designs for each civilization.
I suppose if you manage to get a [GRAB] weapon around someone's throat, you could choke them(with some diifficulty) and thats about it.
Hmmm . . . would the Crime & Punishment arc be improved by including the garrote?
And speaking of entangling with chain weapons, it's high time to mention the gnarliest of them all: The
kusarigama.
Fun Fact #2: Miyamoto Musashi was considered the greatest samurai duelist of all time (he literally wrote the book on the subject), fighting over 60 duels and winning them all through his swordsmanship alone,
except one. When he fought a kusarigama expert, Musashi found that his skill & experience were insufficient to secure victory--he had to lure his opponent into a bamboo grove, where he had less room to swing his chain, enabling Musashi to kill him.
Grabbing a shield with a weapon...? I'm not sure whether that'd be a failure or a success.
If you're wielding a second weapon in your other hand, and yanking their shield aside will come as a surprise to your enemy, then that's likely to be a success. Particularly if the force of your pull on the shield also
turns the enemy, so they can't properly use their own weapon.
Other thoughts:
Footman's flail. Two-handed, taken directly from the agricultural tool--no adaptation required, though metal studs were often added to the business end for combat use. Can be used in close formation if the users limit their strokes to a strict up & down motion (which, incidentally, would probably be devastating against shieldwalls).
All wraparound attacks must be done at
less than the weapon's maximum range.
If this is to be done
right, all weapons should have a Clutter Factor, some way of indicating how much open space (free of obstacles like walls, foliage, furniture, other creatures) is required to use the weapon effectively. Short weapons like axes & maces need only a little, hand-sized weapons like daggers & knuckledusters can be used even while wrestling, thrusting weapons like spears need plenty of room in
one direction, and large, swinging weapons like whips, staves, & 2-handed swords need clear space in
all directions.