Yeah, if you drop the word "only" then the rule makes perfect sense. Including it leads to confusion as to where you place the emphasis in the sentence.
Out of interest, does your opponent get to split his attacks? For example, going with Hardywood's tactic of skink character in the front rank, Krox's in the second to act as an attack magnet. Does your opponent then get to divide his attacks between the two ranks, or can he only focus on one?
No reason he couldn't split his attacks. Both can be targeted, so it would work like he was in base contact with both.
Based on the wording confusion that we see with the rule. If the word 'only' was not in the sentence, then it would be clear that enemy units may attack either skinks or kroxs when the conditions are met. Since the work 'only' is included in the rule, I would agree with original poster saying models MUST target the kroxigor in combat when the conditions are met. This is definitely Rules As Written. That RAW isn't broken since the skink to krox ratio is still 8:1 in a unit, so there are very few wounds of kroxigors in the unit that the enemy must kill before skinks are targeted. Plus kroxigor attack last in combat (and hit hard) thus the enemy would probably WANT to attack the kroxigor so they have several fewer attacks coming their way. However, this would give characters an unprecedented amount of protection in close combat (not that skink heros are that scary in close combat). Skink characters are the only reason to make me lean to thinking the Rule As Intended is that enemy units have a choice in combat to attack either. I would say go over both scenarios with your gaming group and play however you agree to play until the first FAQ states the 'correct' way.
This is probably the way to go until it is cleared up in the FAQ - which I'm sure it will be as there is a lot of people on both sides of the interpretation. I think you're not incorrect to RAW interpret the rule as only being able to attack Krox but I'm I believe that RAI is that the rule is telling you when you are able to attack Krox in the Skrox unit and I'm going to push for that interpretation when I play until the FAQ is out but I won't argue with my opponent if they see it the other way.
I feel like this whole discussion is because people don't know how to read their own language. The sentence is only telling the situations where you are allowed to direct attacks against the krox. Ie. If there are two skinks between the attacker and the krox attacks are not allowed to be directed at the krox and must be on Skinks
I agree that it is open to two interpretations. Now if you take the interpretation that you can only attack Krox, then put a chief in the block, challenge the deamon prince and he has to accept the challenge but can't hit you because you aren't a Krox. That is why I would play it that it is a choice.
sirkently, unfortunately (?) that is not the case, as the challenge rule state that the two challengers are considered to be in base contact only with each other. So even if the rule is you must attack Kroxygors when in base contact with one or with skink who is in base contact with one, you are neither.
I don't see that part in the challenge rules. Just that they are moved into base contact. Now it says they can only direct attacks against each other. Now if you go by the rule that he can only attack a Krox, and army book rules trump BRB rules, he won't be able to hit anything. I could be way off here, but that is one reason why I would go with the interpretation that hitting a Krox is optional, not mandatory.
For challenges the two models are moved within their unit to be in b2b with each other. They can only direct their attacks at their each other and no one else can strike them while in the challenge.
Turning away from the rules debate for a while – what is the benefit of fielding skinks and krox together? It's the kind of thing that looks cool, but if they can just attack skinks and slaughter them surely the krox don't stant much chance against anthing?
You hit the nail on the head: there isn't really much point at all, except to hit your minimum Core with some variety. And even then, you are probably just better off getting more Saurus or Skink Skirmishers. Previously, the Skinks would die but the Kroxigor would ruin monsters and cavalry and stuff. Now the Skinks will die to infantry, so you can't put them into them, and the Kroxigor will die to those monsters and cavalry, so you can't put the unit into them either. You can probably get some viability out of them as flanking units... but then you are probably just better off getting 5 Kroxigor for the same price instead. But then if you are investing 225 points in Special, you're probably just better off getting a Stegadon and paying a little bit extra for the multiple wounds.