Undead warchief on chariot -- why????

[Katie]

So, there I was idly reading my way through the undeads list (OK, not so idle, but long story).

And I find that one's undead warchief can ride a chariot. Woohooo. But... how is this supposed to work?? The minute he goes anywhere at any speed, he loses contact with the cabal (cos they're walking) and you don't get any more necromantic power....

Now, I thought this might be the Italians having got carried away with the special units or something, but it's in Companion. Have I missed some rules that make this useable?

[Tarriel]

I assume from the lack of replies either no onw knows or they cant be arsed to share

[Duff]

We used to have an undead player who occasionally used a chariot, purely to give his warchief a bit more combat oompf, but soon decided it just wasn't worth the extra cost.