crown of command...

[Calahan]

There might be a unit somewhere that doesn't follow the normal rules, but Mictlan's Tlahuelpuchi is not one of them, as they follow the rules just fine. As usually even if a Commander has 0 leadership, you can throw on a Crown/Whip of Command, Sceptre of Authority, or Leper Rod to have them move troops around. This is why I laugh whenever I see players saying "I wish I had some stealthy commanders". And I've used Scouts to ferry undead troops around loads of times.

Indeed depending on various factors (such as a daring trek through enemy lands to their capital), it can be worth (especially for 3 gems with Hammers) using a high stealth Scout or Assasian to command troops rather than whatever national stealth commander is on offer. Since a lot of stealth commanders have a stealth value of just 0, while some nationals or summons can often have 20+, which helps a great deal when it comes to de-stealth checks. (or just use the elite Markata Scouts if you're playing Vanilla).