Wills are an excellent genealogical source. They can name relatives of the deceased and provide information on relationships. They can even tell you whom your ancestor did not like. That's the upside. There is a downside.
Old wills can be vague, unspecific, and downright confusing.
Relationships may not be crystal clear to the modern reader. Phrases or clauses may be reasonably interpreted in more than one way. Such situations are frustrating for the genealogist. Sometimes additional probate records beyond the will may shed light on the problem. It is important to remember that estate records may contain more papers than just the original will or a transcription of that document, and other probate records may clarify what is not clear in the will.