(a) There were holes in Shakespeare's erudition.
In contexts like the above, well-educated Italians, as far as I know, wouldn't use the word "holes" because it seems a bit informal.
In English it appears that a more formal version of the above sentence is:
(b) There were gaps in Shakespeare's erudition.
So, is (b) more formal than (a)? Or, is there a more appropriate word to use in the place of "holes" to have a more formal sentence? Or, lastly, is this not a real problem that it make sense to think about?