This is really a Midwest/Great Lakes issue. There they run 5 groups due to high turn-out.
#1 MW amatuer odd plates
#2 MW amatuer even plates
#3 MW expert odd plates
#4 MW expert even plates
#5 LW expert and amatuer even and odd
Lately, they have combined #3 & #4, reducing the number of practices to 4. Practice #5 is the most crowded, with the biggest difference in speeds between bikes. In most cases, it is impossible to get even 1 clean lap for the faster riders. As a result, most expert LW guys go out with the combined 3 & 4 group, which adds 10 bikes to an already combined group, plus puts 125s and SVs out with 600, 750, and 1000 cc inline fours. Does not make any sense to me.
If this is not happening in your region, than it is probably not an issue for you.