Alter vs Modify vs Change (in Legal Documents)

Consider the quote from "What is a Grantor Trust" article.

This trust is revocable, which simply means it can be altered, modified, and otherwise changed or even terminated during the life of the grantor, provided that the grantor has full mental capacity.

As far as I could figure out from other forums words "alter" and "modified" mean "to change slightly", and "change" is more generic word and may also mean "replace" or "exchange for something else". The text in bold sounds to me like "it can be slightly changed, slightly changed, and otherwise changed". Are there some differences in meaning between "alter" and "modify" in this context or in general? Are they generally interchangeable?

It's your typical legalese. You'll note that lawyers love to use such legal doublets (cease and desist, furnish and supply, e.g.) or triplets (cancel, annul and set aside, e.g.) which for the rest of us are simple synonyms and thus pleonasms.

The following information is culled from the website uslegal.com

Alter is defined as "to cause to become different in some particular characteristic . . . without changing into something else." United States v. Kilbride, 2009 U.S. App. LEXIS 23722 (9th Cir. Ariz. Oct. 28, 2009)

Modification means “any alteration in the terms and conditions of a contract, including supplemental agreements, amendments, and extensions.”