I agree that land provinces in general should be roughly the same size, but there are exceptions. Uncivilised, backwater areas, like the Sahara don't need to have small provinces.
Such areas were almost never fought over (except maybe by some bedouine tribes, dunno), there is no need for many provinces enabling complicated maneuvering actions. Same goes for deep jungle, there are no chokepoints, no points of interest, no centres of transport/industry. Sometimes not even cities.
If you have to decrease the province count in populated, important areas to raise the province count in uninhabited or backwater areas I very much doubt that this would be worth it.
But we'll have to see how the map is made up in the final version.