There may be something in that, although Tranmere, Grimsby and Newport are struggling, all of whom have been promoted fairly recently. Looking at the National League table Chesterfield and Barnet are bossing it (with Bromley in third, bear that in mind for next Saturday).
The three clubs topping league two all have reasonable catchment areas and attendances. Barnet have too much competition to get decent crowds - except for the 12,000 visiting Blackpool fans - and most of the other sides in the NL have similar issues or small catchments. When the Forest Greens of this world return to their unsubsidised level and the historically relatively larger clubs like Yeovil get their financial act together there will be a more fundamental change in the composition of L2.