How many SMALL CAPABLE USER FRIENDLY PMs exist (much less that are for sale at an affordable price.)
The problem would be that purchase of another company would come with the headache of supporting another company.
Well, there is EZClaims, that currently Quasi-connects to AC, but it is not great as a PM.
It would be easier to create links (other than x-link) and allow Docs to choose which PM they would like to use.