I think we need to look at the other possibility before making this assessment.
Lets assume that someone else (Butt, Akmal, Asif) is made captain for the test team. That person will be a part of ODI team as well. Being a test captain, playing under someone else who is senior to you, he will have captaincy ambitions for all formats and THAT my friend, will create divisions more than this possibility!
We need a period of stability and cohesion in these times. Afridi may not have a great test record but he does have the kind of presence in the dressing room that is required right now.