Daniel, Tony, Greg -
It looks to me like Napoleon's original order (in correspondence) assigned 2e leg., 3e and 7e ligne and the RdP to Verdier's division (5 May) but 12e leg (part of Dupas' division, VIII corps) was substituted for the RdP for reasons unknown. At any rate, it seems probable that the RdP never actually joined Lannes' corps as originally ordered by N and went straight to VIII Corps from Danzig.