Napoléon picked Ney, threw him into the deep end and then expected miracles.
Of course he was critcial of Ney - who else to balme other than Grouchy ??
In case Ney would have had the troops promised he could have done a better job - of course there still would be Wellington's army
You should read vPH Verrat - there was a constant trickle of informers - down to humble soldiers who still did porvide excellent information.