At the heart of this issue is the stemming technique used by AppleSearch for search strings. When you enter a wildcard string, you expect AppleSearch to use the entire string, as entered, and the wildcard to find matches. Unfortunately AppleSearch does not do this. It first stems the string and then places the wildcard. It then uses this string to search the index, where the index is composed of stemmed references to document text.
This is how a search for "representing" can find such words like represent, represents, and representative. AppleSearch stems representing to "repres", as do the words represent, represents, and representative. In essence, AppleSearch believes these words are the same, because its index only contains the stemming results, not the whole string.
Unfortunately, stemming is not always a predictable science. From your example, we will use the manage* string. Stemming of this string produces "manage*". However, many of the words desired by the search (such as management, manager, managing, and so on) stem to manag, which is why many of the expected hits are not returned.
Here is a general guideline that should be useful for users that are having problems with search strings:
In general, wildcards are not necessary for AppleSearch queries as stemming provides the same results. When wildcards are unavoidable, try to make the provided information as small as possible, usually four or five characters maximum.