I think what you are asking is how a court will determine which of three persons to choose as guardian for an incapacitated person. I doubt very much that the court will appoint three co-guardians, inasmuch as things would get quite unwieldy. Among the factors that the court will likely take into account are the familial relationship between the incapacitated person and the proposed guardian; the historical relationship; the location of each proposed guardian; the preference of the incapacitated person; and the relative responsibility and trustworthiness of each proposed guardian.
Good luck to you.
Michael S. Haber is a New York attorney. As such, his responses to posted inquiries, such as the one above, are limited to his understanding of law in the jurisdiction in which he practices and not to any other jurisdiction. In addition, no response to any posted inquiry should be deemed to constitute legal advice, nor to constitute the existence of an attorney/client or other contractual or fiduciary relationship, inasmuch as legal advice can only be provided in circumstances in which the attorney is able to ask questions of the person seeking legal advice and to thus gather appropriate information. In addition, an attorney/client relationship is formed only by specific agreement.
I agree with Attorney Haber that it is unlikely three people would be considered as co-guardians. Whether two would be considered depends on who those people are.
More information is needed before we can really help you. The relationship to the adult is certainly a consideration. Co-guardianship would work the same way as a standard guardianship, except that two people would be responsible for making reports to the court and making decisions regarding the ward's care and well-being. I have seen this work out very well, provided the co-guardians get along and relate well with each other. If they do not, then this is not a good idea.