I run both after the reset. Fairly new to both of them but I’ll try to explain why I run them.
Smilonemys is good against the Apexes. It walls Hadros Lux and Ceramagnus with its 50% Armor, Shields and Distraction, while Mortem gets Distracted and you can Dodge its attacks with Deliberate Prowl, while dishing out good damage with Precise Pounce and Rampage and Run. It has great mobility with the latter move and Swap-In Stun (which I would like to see buffed to 100%, but that’s a different topic). The only thing letting it down is the Health, I’d like it to have a bit more Health. But other than that, it does its job terribly well. The fact that it has all forms of damage mitigation really makes it versatile against a lot of opponents.
Mine is boosted at 151 speed to make sure I outspeed some speedless Hadros Lux if they do not double Resilient me, with the rest divided in Attack and Health.
Trebax is a good revengekiller like you mentioned with its Revenge Nullifying Rampage, and Cautious Impact is arguably the best Distraction move out there aside from maybe Super Distraction and Revenge Distracting Impact. With this move, Trebax suddenly survives a lot of hits thanks to Dodge and Distraction, allowing it to take on powerful creatures like Mortem Rex, Magnapyritor, Acrocanthops, etc. It has great stats too, and the 113 speed can be augmented by Speed Boosts. Remember that both Cautious Impact and its basic attack give it a Speedup effect, allowing it to become faster on its own. The one downside to Trebax is that it just horribly loses to the two Resilient Apexes. Hadros Lux in particular just shuts it down completely, even when swapping into one of its attacks. That is my main gripe with Trebax when playing it, as it just horribly loses to those Resilient creatures.
Trebax needs some speed. Mine sits at 137 speed, allowing it to hit that great 150 speed mark after a speedup move. I’ve debated on either dumping everything else in attack for maximum power or taking some Health boosts as well to make it more bulky. Decided on the Health part, and mine will likely become 6/12/12, but I might play around with more Attack and less Health.
Ultimately, I’ll be running both though, as they play different roles to each other. Smilonemys is a great Mortem Rex counter and Hadros/Magnus check while also being able to give your team momentum with swappers like Magnus, Dracoceratops and Monolorhino. Trebax is a great revengekiller and when saved at the end of a game can be extremely lethal. Hopefully this has helped you a bit!