Hi Swami !
>average engines like Danasah,Hermann,BugChess,Ruffian,Delfi,RDChess play a lot more than their own level at blitz.
This does not seem true at least for BugChess2 if we look at the CCRL and compare 40/40 (2667 +- 37) and 40/4 (2646 +-1 7) ratings : BugChess2 seems better at longer time control at least in the CCRL conditions (engine own book disabled, tournament style time control).
If you have results showing the opposite with as many 40/40 games, i am interested, l did not get a cluster for christmas

Maybe the use of BugChess2's own book (probably not good at all) and different time control styles (tournament time control vs sudden death for instance) can change this tendency somewhat.
Cheers
François