As bas_2312 stated other K’daai in base contact do not take hits.
If an enemy unit is in contact with a unit of 2 K’daai they would only take 2 blazing body hits and then 2 stomp hits at the end. Worth mentioning K’daai units are 3+ minimum.
And yes the rules are the same for the destoryer/fireborn. They have the same bestiary entry. The destroyer has some additional rules however. Terror rather then fear, large target (no idea why this is there), frenzy, +d3 attacks each turn.
Actually when I made that comment I forgot that there were actual rules for large targets, even though you no longer get the +1 to hit when shooting. If I remember correctly they can’t use cover as they are considered to large.
Yeah, that’s actually all it is, unless he’s the General or being ridden by the General. It’s a pretty nothing rule, really, but it’s standard for any Monster with 5 or more Wounds, so it would be weird if the Destroyer didn’t have it.