I have been fielding units of 32 skinks c/w 4 krox in horde formation. Since the krox form 80% of the second rank, do the 8 skinks behind them also get to attack? So far, I have been going with 14 skink + 12 krox attacks but it would be nice to toss in the extra 8 skinks if it is legit.
Rule is unclear because GW mucked up the wording of rule for the extra rank of supporting attacks for hordes. The rule is clear for non-horde or in the extra attacks section, but the hordes section doesn't make it clear what it means by a third rank. Standard supporting attacks have a good definition, you have to be behind a front ranker eligible to fight. Supporting attacks including units with extra attack rule are also clear whether or not unit counts as horde. The confusion happens because of the rules about calculating rank bonusses in units with models with different base sizes. A skink behind a krox in a skrox unit is in the third rank because there are two ranks in front of it but counts as being in a fourth rank for calculating rank bonusses and depth of unit for stead fast. Skink behind krox behind front rank skink gets to fight if unit a 10 skink wide horde, but a krox couldn't fight in the same position because the skrox units can only have krox in 2nd rank (or first if too many skinks dead!).