Does a monster you have trained from a low level have higher stats than one you catch in the wild at the same level? Or are they the same.

They are the same

They are the same. I don’t think arkadions have unique stats. The only thing that may differentiate between two, same-leveled species is the grade, which doesn’t affect stat at all.

++Deadpool ninja’d me. ^^

That includes, too, if you get a monster’s evolved form at level 1 versus getting the monster in its first form and evolving it. 

But it’s a good concern - monsters could gain x amount of stats depending on its star rank and other properties, and when it evolves the current stats carry over. And then it gains more each level from there. That would be the easier way to code the game.

In Hunter Island, however, it appears that stats are fixed by level and don’t carry over.