If a mixed unit of Skinks & Kroxigors have enough Skinks left alive to fill the front row (or whatever row/column is in b2b), can only Skinks be attacked in combat? If you have 10 Skinks left in your unit and the unit suffers 12 wounds in combat, do the extra wounds carry over to the Kroxigor or are the extra wounds discarded? If they are discarded to they still count toward combat resolution?
Yes, if there are skinks enough to fill the front rank, the kroxigors cannot be targeted. If you have 10 skinks and 12 wounds, they 2 additional wounds are lost because of the different profile of the kroxigor. Your opponent cannot designate the seperation of attacks until there is a Kroxigor in b2b with his unit. Those lost wounds do not count for combat rez either.
The one caveat with regard to wounding kroxigor in a skrox unit is when the enemy has different initiative values. If the faster troops manage to kill off enough skinks to force a krox into the front rank then the slower troops/attacks can be directed onto the krox. Otherwise, it is exactly as Arli has indicated - the krox are nearly untouchable. This is one of the reasons why I think every lizzie army should have at least one unit of skrox in order to deal with big monsters. The unit can't be stomped, is steadfast and will likely grind down any big monster over time (even S2 skinks will wound on occassion!!) while only losing skinks in exchange!!
If there is only a few skinks left can the opponent only roll half his attacks, resolve them and then target the krox after?
He can choose to target any kroxigor that are in base contact during that phase of combat. Say they where fighting a unit of knights. skinks might have the highest initive and go first, then the knights probaly go then the horses and kroxigors go last because of greatweapons. so if the knights kill enough skinks, some of the horses might find themselves in base contact with some of the kroxigors, and therefore be able to attack them.
But at the start of the knights turn if there is no kroxigor in base contact they can't attack the krox's. Even if they finish off the skinks with half their attacks. Gotcha.
Yes all attacks at the same initiative are simultaneous, all simultaneous attacks need to be allocated (it is generally assumed that attacks not specifically allocated are against the standard R&F trooper. Problem with skrox is that there are two different R&F troopers. According to rules attacks still need to be allocated so attackers need to specify which attacks are against which target before rolling and according to rules hits can't transfer, so if no krox eligible before attack no hits can be allocated. An obscure circumstance can occur when a krox is in front rank while there are eligible skinks still in rear ranks (requires an ongoing combat with either flank attacks or magic bringing skinks back to life). In these cases the front rank krox is actually in a different "pool" of troops from rear rank krox as the ear rankers are ineligible to be targetted. Skinks will step forward if the front rank krox is killed so any overkill will be lost as it will neither transfer to stepping forward skinks nor ineligible target rear rank krox. Extra hits/wounds on front rank krox will only transfer to rear rank krox if all skinks eligible to step forward are killed and a krox has to step forward to maintain unit width.