Average speed is not a criteria for allotting LHB rakes.
There are no priorities for alloting LHB coaches. Each zone will allot LHB rakes to a train based on the maintenance capacity of the CDO, remaining codal life of the ICF rakes, staff availability and other operational factors. LHB coaches are an upgrade to ICF coaches and all trains will have to be upgraded to LHB coaches, be it a prestigious SF or an all-stopping passenger.
Too much attention has been given in the media about the '160kmph+' capable LHB coaches. LHB...
more... coaches were NOT IMPORTED for their speed capabilities. They were imported for their modern design and as an upgrade to the ICF coaches. The higher speed capacity is just a secondary advantage (ICF Shatabdi rakes too ran at 140+ kmph with the Bhopal Shatabdi).
Raj and Shatabdi trains were first converted to LHB as the initial designs of the LHB coaches were only for A/C coaches and IR needed a lot of time to design non A/C versions of the same coaches.