Hello Carli, Rene,
Appart of dedicated professionals from each area under investigation.
Architects – on each level (Business, Application, Databases, Infrastructure)
Process Analysts – especially on Business level
and someone from Change Management.
(I think something extremely important is to validate readiness for merge/acquisition on both sides).
Next point… Program Manager and 2 – 3 independent consultants to validate and present results of final documentation analysis