I wasn't a tester, so I'm pretty unfamiliar with the new stuff. When is it a good idea to turn someone into a zombie? How much silver should I pack? What are some key common & uncommon items I should keep an eye out for in the shops? And so on.
At the end of the round, your warrior on 3 health, now is the time to turn them into a zombie. They're already screwed, why not let them get one last burst of damage? Otherwise, zombie form is bad. very bad.
The only other time I can think of is when your team-mate is wearing arrogant armor, as this will protect them from the zombie form and just give them double card draw.
Or of course when you want to turn the enemy into a zombie, which is when you think they are out of moves and therefore can't use their new cards, very strong with inq bolt.
You can also Vanguard your tripped and rooted teammates away from danger (like any other move ability triggered by a teammate).
Team Walk and Team Shift won't work in this instance. The keyword on most team move style cards, like Walk, Team! is push allies, but Team Walk and Team Shift have the move keyword, which is prevented by halt. The rule of thumb here is that ___, Team! cards will work on a halted char, while Team ____ cards won't. Push moves another character under the original character's control, while move allows them to move under their own control. The difference here is mostly noticeable in co-op.