Skill: Make guesses as to what the opponent has in store. It’s not that hard if you know the game, the meta and the usual teams in the arena.
Skill: Make guesses as to whether your opponent will switch or not, and be prepared for both. For instance, when I’m finishing off a dinosaur, some times I will do so with a big hit instead of a small one if I see the opponent might switch to avoid dying. And many times I’m right and the next opponent gets hurt a lot.
Skill: Build a decent, versatile team so that no matter which random 4 dinosaurs you get, you can make them work.
Skill: Not just know your rotation, but also your opponent’s rotation. Calculate when they are going to use certain abilities. For instance, an Ankylosaurus will try to use the 100% shield to prevent your biggest hit. Surprise them with a small hit when they will most likely use that 100% shield. Anticipate.
Skill: choose your dinosaur order correctly. Opening with a raptor might be dangerous but don’t leave them for the end either, or you won’t survive that almost mandatory last switch.
Not denying that there’s a strong luck element in the game. All crits are based on luck, and so are most stuns and cloaks. However when either a stun or a crit surprises you, it takes skill to still turn the tables in your favor. I’m gonna say it has both, but more skill than luck. Of course, if you get ridiculously unlucky in a match, you don’t have a chance at winning, but most of the time, skill is way more important.