Standardising the user id field across Joomla core tables

[easistudio]

I've noticed when viewing the core tables in PHPMyAdmin that there doesn't seem to be any standardisation of the user id field across joomla core tables.

To illustrate my point, please first view the "users" table and in particular the id field which is of variety int(11).
Now view the categories table and look down to see 3 fields named "checked_out", "created_user_id" and "modified_user_id". All 3 fields reference the id field of the "users" table but bizarrely "created_user_id" and "modified_user_id" are int(10) while "checked_out" is an int(11).

I appreciate it is highly unlikely that any website will have a membership that will warrant any actual concerns but it doesn't really make much sense (to me anyhow) having fields of a different length supposedly storing the same data.

Edit
In much the same argument, the id field in the category table is an int11 but catid (which references the id field in the category table) in the content table is an int10.