The formations for Traitor's Hate have leaked. What that does for Chaos is debatable and will surely unfold over the next few weeks, however there are two formations that begin to open a can of worms: The Heldrake Terror Pack and the Terminator Annihilation Force. First up, Helturkeys.
Now this isn't so much a conundrum as it is a clearly NOT thought out special rule. Read over the Merciless Pursuit rule. If you vector strike a unit that has gone to ground, is falling back or pinned, they get d6 hits instead of 1. The RAI make it GREAT but the RAW makes it really meh and extremely unlikely to ever occur. Why? Well Vector Strike is during your movement phase. Who is ever gone to ground during your movement? Who is ever pinned during your movement? And falling back is possible, but not always likely. It is most likely right after your shooting or assault phase, and they have a chance to regroup during your opponents turn.
The problem is that during YOUR shooting phase you may pin and force units to go to ground. They will remain that way until the END of your opponents turn, BEFORE you ever get another movement phase and have a chance to vector strike. Now technically I guess that these things can happen as a result of overwatch, but that is extremely unlikely. No one ever goes to ground from overwatch (because your charge auto fails, so why assault and subject yourself to the shooting) and the chances of charging a pinning weapon is slim, and then you still have to get pinned by it!
So really this is kinda a failure of a rule and needs an errata, which is sad because the rules technically have not even released.
The second one is an actual conundrum and is with the Terminator Annihilation Force.
It is a pretty neat formation that allows you to get a free shooting right after "deploying by deep strike" so long as you target your "targeted unit", which you can continually update whenever the targeted unit is destroyed. Pretty straight forward since you can "deploy by deep strike" only once, right? Well, what about Gate of Infinity in Daemonology Sanctic?
Gate allows you to remove your unit and then that unit "immediately arrives using the rules for deep strike". So that is not deployment, BUT when you go to deep strike (BRB 162) under "Arriving by Deep Strike" you "deploy them as follows".
So the question is, can you deploy your unit multiple times? Does this just work any time you deep strike or only after the 1st time? To me this kinda a RAI opposite of the above, where it was meant to be okay and has a potential to abuse via RAW. Probably supposed to work only once, but I know this should be clarified when GW inevitably asks for/answers Traitor's hate FAQs.