I don't get the point in the power level discussions between Ash's Pokemon, since at the end of the day, each Pokemon will be as strong or as weak as the plot requires it to be.. There is no definite "this pokemon is stronger than this one" because one day you get a Pokemon flooring everything in sight and the next it can't even take down something considered generally weak, whilst another team member gets the spotlight..
Is Lycanroc one of Ash's strongest? Sometimes. Is Bulbasaur one of Ash's strongest? Sometimes. Is freaking Scraggy one of Ash's strongest? If the plot requires it to be, then yeah sure.. Its all to do with the power of the plot..