(Answered) Missing all four limbs and immobile

[Empyrus]

BMM page 15, since first printing, notes that a mech missing all four limbs is immobile.
Total Warfare however, makes no mention of such thing. Page 122 does note that a quadmech without all legs is immobile.

Is BMM correct here and TW is merely lacking mention of this (not in errata either as far as i can see), or is BMM's notion mistaken and only quad mechs should be immobile when missing all limbs?

(Also, in case of tripods, if BMM is correct, should they lose all 5 limbs to be immobile rather than merely 4?)

[Xotl]

The BMM (and AGOAC) is right; TW is missing a mention of this.  It was something decided on during the making of the BMM and so is a rules change, but it was never properly ported over because TW doesn't have a nice centralized Immobile section to errata, and the issue of missing two different types of limbs doesn't really fit anywhere but there.  But I'll see about cramming it somewhere into TW and getting it into the errata doc.