There is a good reason why the flanges and disc faces should be very carefully cleaned and bolted together dry.
Unless the coat of grease is completely uniform without any specks of grit or dirt (highly unlikely) you will introduce run out to the disc (extremely likely).
When I fit discs, I
always check them for run out with a DTI, and if excessive I will remove and recheck the surfaces, and even rotate the disc on the flange irrespective of whether the retaining CSK screw is in alignment to obtain the best figures.
Brian
