Alphabetizing, or any canonical ordering, can help minimize merge conflicts. We require it for Java imports and lists all over, so I'm not surprised to see it here.
In some projects I've worked on, we allow logical groupings, provided comments that describe what they are, but then require alphabetizing within the groups.
In some projects I've worked on, we allow logical groupings, provided comments that describe what they are, but then require alphabetizing within the groups.