Sorry, said the wrong model, the Harbinger has the additional armor.I don't recall ever hearing the Warden had different armor and engines. Do you remember where that comes from?
Is the Harbinger more heavily armored than the Warden and Sentinel?
Yes, the Harbinger has additional armor.
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But also in the same Q&A it says:
Are the cockpit differences purely cosmetic or are they functionally different? (Sentinel’s AR cockpit, Harbinger’s armored panels)
So all I can say about that is: Oh, bum. Got that wrong didn't I?The cockpits are functionally different. The Sentinel features an AR cockpit, discussed above, and the Harbinger’s cockpit includes additional armored panels to protect the pilot. These upgrades are included in the BUK packages.