Never change the order of any names in a document. Children could (but not necessarily) be listed in order of age in a will. If an older child is listed last in a census enumeration it may mean that they weren't really living there or had moved back home (or it could just be an "error" on the part of the census taker). Heirs may be listed in order of age on a quit claim deed (or they may not).
The order may be a clue, but try and use other documentation to back up any conclusions you make about the order.
And remember that order, sometimes like life, may be completely random and meaningless.