Just adding the word may have provided accuracy when one could have missed it out. But is it true?
The writer says two movies “considerably” dominated the Oscars one year. In context, this may be more correct than just dominated. But if you look closer, there were three films that dominated.
The second film, which won in the main categories, may have done considerably better than the third film, which won the same amount of awards but in minor categories.
If one considers that the main categories are heftier than the minor ones, yes, two films considerably dominated the awards.
The writer placed the adverb considerably before the form of the verb dominated. Actually, dominated is what is called the past participle (or form of the verb). Why does this grammar matter? Because only two films considerably dominated the Oscars that year. But is that true?
Are we convinced that sometimes we should always include the adverb? It may be most accurate. Or perhaps that is a matter of perception if a picture is better than a song from a picture.
However, only one film dominated the Oscars that year in terms of the amount of awards it won outstripped everything else. But the writer insisted that Best Picture and Best Actor nods, in spite of another film with better statistics, are just as important if not more so, and a film which won Best Song and two other awards is just not as important.
Perhaps the lesson here is that the writer’s perception is what is been taken into account.