Perhaps a range for each attribute from 1-20 will be better. Its arbitrary but its still more useful than just 1-10.

For eg. no matter how strong Optimus or Galvatron are, they can't possibly be as strong as Superion or worse Predaking. Yet they all rank the same - 10/10.

The rating system either should group characters according to categories, or (my preference) at least have an extensive enough scale for the attributes to be feasible and meaningful.

Example:
Strength:
Metroplex - 20+
Omega Supreme - 18
Sky Lynx - 17
Superion - 18
Optimus Prime - 10
Grimlock - 9.5

etc...

Additionally, some attributes should be further divided or at least made clearer - Speed is confusing. Leave Speed and add another attribute, Agility. Better?

All these revisions should make things and the universe a whole lot more comprehensive and enhance continuity.